Transmission method, transmission device, reception method and reception device

ABSTRACT

A transmission method includes mapping processing, phase change processing, and transmission processing. In the mapping processing, a plurality of first modulation signals and a plurality of second modulation signals are generated using a first mapping scheme, and a plurality of third modulation signals and a plurality of fourth modulation signals are generated using a second mapping scheme. In the phase change processing, a phase change is performed on the plurality of second modulation signals and the plurality of fourth modulation signals using all N kinds of phases. In the transmission processing, the first modulation signals and the second modulation signals are respectively transmitted at a same frequency and a same time from different antennas, and the third modulation signals and the fourth modulation signals are respectively transmitted at a same frequency and a same time from the different antennas.

This application is a Continuation of U.S. application Ser. No.15/493,562, filed Apr. 21, 2017, which is a Continuation of U.S.application Ser. No. 15/341,558, filed Nov. 2, 2016, now U.S. Pat. No.9,667,326, which is a Continuation of U.S. application Ser. No.15/134,014, filed Apr. 20, 2016, now U.S. Pat. No. 9,520,934, which is acontinuation of PCT/JP2014/005436 filed Oct. 28, 2014.

BACKGROUND 1. Technical Field

The present disclosure relates to a data transmission method, a datareception method, a data transmission device, and a data receptiondevice. For example, the present disclosure relates to compatibilitybetween improvement of a data transmission rate and data transmissionwith good reception quality in picture data distribution throughbroadcasting.

2. Description of the Related Art

Conventionally, for example, there is a communication method called MIMO(Multiple-Input Multiple-Output) as a communication method in which amulti-antenna is used. In the multi-antenna communication typified bythe MIMO, the transmission device modulates pieces of transmission dataof a plurality of sequences, and simultaneously transmits the modulatedsignals from different antennas, thereby enhancing a data communicationrate.

CITATION LIST Patent Literature

PTL 1: International Patent Publication No. 2005/050885

Non-Patent Literatures

NPL 1: “Achieving near-capacity on a multiple-antenna channel” IEEETransaction on communications, vol. 51, no. 3, pp. 389-399, March 2003.

NPL 2: “Performance analysis and design optimization of LDPC-coded MIMOOFDM systems” IEEE Trans. Signal Processing, vol. 52, no. 2, pp.348-361, February 2004.

NPL 3: “BER performance evaluation in 2×2 MIMO spatial multiplexingsystems under Rician fading channels,” IEICE Trans. Fundamentals, vol.E91-A, no. 10, pp. 2798-2807, October 2008.

NPL 4: “Turbo space-time codes with time varying lineartransformations,” IEEE Trans. Wireless communications, vol. 6, no. 2,pp. 486-493, February 2007.

NPL 5: “Likelihood function for QR-MLD suitable for soft-decision turbodecoding and its performance,” IEICE Trans. Commun., vol. E88-B, no. 1,pp. 47-57, January 2004.

NPL 6: “Shannon Genkai e no Michishirube (Signpost to the Shannonlimit): “Parallel concatenated (Turbo) coding”, “Turbo (iterative)decoding”, and it surroundings”, Technical report of IEICE. IT98-51.

NPL 7: “Advanced signal processing for PLCs: Wavelet-OFDM,” Proc. ofIEEE International symposium on ISPLC 2008, pp. 187-192, 2008.

NPL 8: D. J. Love, and R. W. Heath, Jr., “Limited feedback unitaryprecoding for spatial multiplexing systems,” IEEE Trans. Inf. Theory,vol. 51, no. 8, pp. 2967-1976, August 2005.

NPL 9: DVB Document A122, Framing structure, channel coding andmodulation for a second generation digital terrestrial televisionbroadcasting system (DVB-T2), June 2008.

NPL 10: L. Vangelista, N. Benvenuto, and S. Tomasin, “Key technologiesfor next-generation terrestrial digital television standard DVB-T2,”IEEE Commun. Magazine, vo. 47, no. 10, pp. 146-153, October 2009.

NPL 11: T. Ohgane, T. Nishimura, and Y. Ogawa, “Application of spacedivision multiplexing and those performance in a MIMO channel,” IEICETrans. Commun., vo. 88-B, no. 5, pp. 1843-1851, May 2005.

NPL 12: R. G. Gallager, “Low-density parity-check codes,” IRE Trans.Inform. Theory, IT-8, pp-21-28, 1962.

NPL 13: D. J. C. Mackay, “Good error-correcting codes based on verysparse matrices,” IEEE Trans. Inform. Theory, vol. 45, no. 2, pp399-431, March 1999.

NPL 14: ETSI EN 302 307, “Second generation framing structure, channelcoding and modulation systems for broadcasting, interactive services,news gathering and other broadband satellite applications,” v. 1.1.2,June 2006.

NPL 15: Y.-L. Ueng, and C.-C. Cheng, “a fast-convergence decoding methodand memory-efficient VLSI decoder architecture for irregular LDPC codesin the IEEE 802.16e standards,” IEEE VTC-2007 Fall, pp. 1255-1259.

NPL 16: S. M. Alamouti, “A simple transmit diversity technique forwireless communications,” IEEE J. Select. Areas Commun., vol. 16, no. 8,pp. 1451-1458, October 1998.

NPL 17: V. Tarokh, H. Jafrkhani, and A. R. Calderbank, “Space-time blockcoding for wireless communications: Performance results,” IEEE J.Select. Areas Commun., vol. 17, no. 3, pp. 451-460, March 1999.

SUMMARY

In one general aspect, the techniques disclosed here feature atransmission method including: mapping processing of generating aplurality of first modulated signals s1 and a plurality of secondmodulated signals s2 using a first mapping scheme, the plurality ofsecond modulated signals s2 being equal to the plurality of firstmodulated signals s1, and generating a plurality of third modulatedsignals s3 and a plurality of fourth modulated signals s4 using a secondmapping scheme, the plurality of fourth modulated signals s4 being equalto the plurality of third modulated signals s3, each of the firstmapping scheme and the second mapping scheme involving 16 signal points,the first mapping scheme and the second mapping scheme being differentfrom each other in a signal point arrangement; phase change processingof performing a phase change on the plurality of second modulatedsignals s2 using all N kinds of phases, and performing the phase changeon the plurality of fourth modulated signals s4 using all the N kinds ofphases, the N being an integer of 2 or more; and transmission processingof transmitting sequentially the plurality of first modulated signals s1and the plurality of third modulated signals s3 using a first antenna,transmitting each of the plurality of second modulated signals s2subjected to the phase change using a second antenna at a same frequencyand a same time as a frequency and a time of a corresponding one of theplurality of first modulated signals s1, and transmitting each of theplurality of fourth modulated signals s4 subjected to the phase changeusing the second antenna at a same frequency and a same time as afrequency and a time of a corresponding modulated signal of theplurality of third modulated signals s3.

These comprehensive and specific modes may be implemented by anycombination of the systems, devices, and methods.

Further advantage and effect according to one aspect of the presentdisclosure are disclosed from the specification and drawings. Althoughthe advantage and/or the effect is provided by the feature described inthe exemplary embodiment, specification, and drawings, all theadvantages and/or the effects are not necessarily provided in order toobtain at least one feature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating configuration examples of transmission andreception devices;

FIGS. 2A and 2B are views illustrating examples of simulation results ofa BER (Bit Error Rate) characteristic (vertical axis: BER and horizontalaxis: SNR (signal-to-noise power ratio)) when 2-by-2 (2-antennatransmission and 2-antenna reception) spatially multiplexed MIMO isperformed on data subjected to LDPC (low-density parity-check) coding ina Rayleigh fading environment and a Rician fading environment withRician factor K=3, 10, and 16 dB;

FIG. 3 is a view illustrating an example of a 16 QAM signal pointarrangement in an in-phase I-orthogonal Q plane;

FIG. 4 is a view illustrating another example of the 16 QAM signal pointarrangement in the in-phase I-orthogonal Q plane;

FIG. 5 is a view illustrating an example of the 16 QAM signal pointarrangement in the in-phase I-orthogonal Q plane;

FIG. 6 is a view illustrating an example of a 64 QAM signal pointarrangement in the in-phase I-orthogonal Q plane;

FIG. 7 is a view illustrating another example of the 64 QAM signal pointarrangement in the in-phase I-orthogonal Q plane;

FIG. 8 is a view illustrating still another example of the 64 QAM signalpoint arrangement in the in-phase I-orthogonal Q plane;

FIG. 9 is a view illustrating an example of a 256 QAM signal pointarrangement in the in-phase I-orthogonal Q plane;

FIG. 10 is a view illustrating another example of the 256 QAM signalpoint arrangement in the in-phase I-orthogonal Q plane;

FIG. 11 is a view illustrating still another example of the 256 QAMsignal point arrangement in the in-phase I-orthogonal Q plane;

FIG. 12 is a view illustrating a configuration example of signalprocessing of a transmission device;

FIG. 13 is a view illustrating another configuration example of thesignal processing of the transmission device;

FIG. 14 is a view illustrating a configuration example of signalprocessing after the signal processing in FIG. 12 or 13;

FIG. 15 is a view illustrating an example of a frame configuration inwhich MIMO is used;

FIG. 16 is a view illustrating a relationship between the transmissiondevice and the reception device;

FIG. 17 is a view illustrating an example of a phase change;

FIG. 18 is a view illustrating another configuration example of thesignal processing after the signal processing in FIG. 12 or 13;

FIG. 19 is a view illustrating still another configuration example ofthe signal processing after the signal processing in FIG. 12 or 13;

FIG. 20 is a view illustrating still another configuration example ofthe signal processing after the signal processing in FIG. 12 or 13; and

FIG. 21 is a view illustrating still another configuration example ofthe signal processing after the signal processing in FIG. 12 or 13.

DETAILED DESCRIPTION

(Underlying Knowledge Forming Basis of the Present Disclosure)

FIG. 1 illustrates configuration examples of transmission and receptiondevices for two transmit antennas, two receive antennas, and twotransmission modulated signals (transmission streams). In thetransmission device, coded data is interleaved, the interleaved data ismodulated, frequency conversion is performed on the modulated data togenerate a transmission signal, and the transmission signal istransmitted from the antenna. At this point, a scheme in which differentmodulated signals are transmitted from transmit antennas at the sameclock time and the same frequency is a spatially multiplexed MIMOscheme.

PTL 1 discloses a transmission device including different interleavingpatterns for different transmit antennas. That is, in the transmissiondevice of FIG. 1, two interleavers (πa and πb) have the interleavingpatterns different from each other. In NPLs 1 and 2, in the receptiondevice, the reception quality is improved by iteratively performing adetection method (the MIMO detector in FIG. 1) in which a soft value isused.

An NLOS (non-line of sight) environment typified by a Rayleigh fadingenvironment and an LOS (line of sight) environment typified by a Ricianfading environment exist as an actual propagation environment model inradio communication. The transmission device transmits a singlemodulated signal, and the reception device performs a maximum ratiocombination on signals received by the plurality of antennas, anddemodulates and decodes the signal after the maximum ratio combination.In such cases, the reception device can obtain good reception quality inthe LOS environment, for example, the environment having a large Ricianfactor indicating magnitude of received power of a direct wave toreceived power of a scattered wave. However, depending on thetransmission scheme (for example, spatially multiplexed MIMOtransmission scheme), it is necessary for the reception device toaddress a problem in that the reception quality degrades with increasingRician factor (see NPL 3).

FIGS. 2A and 2B illustrates examples of simulation results of a BER (BitError Rate) characteristic (vertical axis: BER and horizontal axis: SNR(Signal-to-Noise power Ratio)) when 2-by-2 (2-antenna transmission and2-antenna reception) spatially multiplexed MIMO is performed on datasubjected to LDPC (Low-Density Parity-Check) coding in a Rayleigh fadingenvironment and a Rician fading environment with Rician factor K=3, 10,and 16 dB.

FIG. 2A illustrates the BER characteristic of a Max-log-APP (APP: APosterior Probability) in which iterative detection is not performed(see NPLs 1 and 2), and FIG. 2B illustrates the BER characteristic ofthe Max-log-APP in which the iterative detection is performed (a numberof iterations is 5) (see NPLs 1 and 2).

As can be seen from FIGS. 2A and 2B, in the spatially multiplexed MIMOsystem, irrespective of the iterative detection, the reception qualitydegrades with increasing Rician factor in the reception device. Thisshows that the spatially multiplexed MIMO system has a uniquecharacteristic that “in the spatially multiplexed MIMO system, thereception quality degrades in the reception device when the propagationenvironment is stabilized” unlike the conventional system that transmitsthe single modulated signal.

The broadcasting or the multi-cast communication is a service that needsto cope with various propagation environments, and the radio wavepropagation environment between a receiver owned by a user and abroadcasting station can be the LOS environment. In the case thatspatially multiplexed MIMO system having the characteristic is used inthe broadcasting or the multi-cast communication, the service may beunavailable due to the degradation of the reception quality even if theradio wave has high reception field intensity in the receiver.

That is, in order to use the spatially multiplexed MIMO system in thebroadcasting or the multi-cast communication, there is a demand fordevelopment of the MIMO transmission scheme in which a certain level ofreception quality is obtained in both the NLOS environment and the LOSenvironment.

NPL 8 discloses a method for selecting a code book used in pre-coding(pre-coding matrix (also referred to as a pre-coding weight matrix))from feedback information transmitted from a communication partner.However, as described above, NPL 8 does not disclose a method forperforming the pre-coding in the situation in which the feedbackinformation cannot be obtained from the communication partner in thebroadcasting or multi-cast communication.

On the other hand, NPL 4 discloses a method for switching the pre-codingmatrix with time, the method being applicable to the case that thefeedback information does not exist. NPL 4 discloses that a unitarymatrix is used as a matrix used in the pre-coding or that the unitarymatrix is randomly switched.

NPL 4, which discloses the simply random switching, does not disclose amethod applied to the degradation of the reception quality in the LOSenvironment. Neither description about the pre-coding method forimproving the degradation of the reception quality in the LOSenvironment nor a method for constructing the pre-coding matrix isdescribed in NPL 4.

NPL 4 does not disclose a signal point arrangement (mapping) in thein-phase I-orthogonal Q plane of the modulation scheme in applying thepre-coding, for example, a mapping method for improving the datareception quality in the LOS environment.

Hereinafter, an exemplary embodiment of the present disclosure will bedescribed with reference to the drawings.

The present disclosure relates to a transmission method for improvingthe quality of the received data in the reception device when the MIMO(Multiple-Input Multiple-Output) scheme involving the plurality oftransmit antennas and the plurality of receive antennas is used in themulti-cast transmission or the broadcasting.

A probability of increasing a minimum Euclid at the signal point in thein-phase I-orthogonal Q plane during the reception is increased in theradio wave propagation environment in which the direct wave is dominant,which allows the reception device to improve the quality of the receiveddata.

An exemplary embodiment dealing with the characteristic will bedescribed below.

First Exemplary Embodiment

First, a mapping method (a signal point arrangement in an in-phaseI-orthogonal Q plane of a modulation scheme) according to the exemplaryembodiment will be described with 16 QAM, 64 QAM, and 256 QAM mappingmethods as an example.

<16 QAM Mapping>

The 16 QAM mapping method will be described below.

FIG. 3 illustrates an example of a 16 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 3, 16 marks “◯” (whitecircle) indicate the 16 QAM signal points, a horizontal axis indicatesan in-phase component I, and a vertical axis indicates an orthogonalcomponent Q.

In FIG. 3, f>0 (f is a real number greater than 0), f≠3, and f≠1 hold.

In the in-phase I-orthogonal Q plane, coordinates of the 16 signalpoints (in FIG. 3, the mark “◯” indicates the signal point) for 16 QAMare expressed as follows:

-   (3×w_(16a), 3×w_(16a)), (3×w_(16a), f×w_(16a)), (3×w_(16a),    −f×w_(16a)), (3×w_(16a), −3×w_(16a)), (f×w_(16a), 3×w_(16a)),    (f×w_(16a), f×w_(16a)), (f×w_(16a), −f×w_(16a)), (f×w_(16a),    −3×w_(16a)), (−f×w_(16a), 3×w_(16a)) (−f×w_(16a), f×w_(16a)),    (−f×w_(16a), −f×w_(16a)), (−f×w_(16a), −3×w_(16a)), (−3×w_(16a),    3×w_(16a)), (−3×w_(16a), f×w_(16a)), (−3×w_(16a), −f×w_(16a)),    (−3×w_(16a), −3×w_(16a)), where w_(16a) is a real number greater    than 0.

In FIG. 3, the bits to be transmitted (input bits) are set to b0, b1,b2, and b3. For example, the bits to be transmitted(b0,b1,b2,b3)=(0,0,0,0) are mapped in signal point H101 of FIG. 3 and(I,Q)=(3×w_(16a), 3×w_(16a)) is obtained, where I and Q are the in-phasecomponent and the orthogonal component of the post-mapping basebandsignal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 16 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3). An example of the relationship betweena set of b0, b1, b2, and b3 (0000 to 1111) and the coordinates of thesignal point is indicated in FIG. 3. FIG. 3 illustrates the values ofthe sets of b0, b1, b2, and b3 (0000 to 1111) immediately below the 16signal points (the marks “◯” in FIG. 3) of 16 QAM:

-   (3×w_(16a), 3×w_(16a)), (3×w_(16a), f×w_(16a)), (3×w_(16a),    −f×w_(16a)), (3×w_(16a), −3×w_(16a)), (f×w_(16a), 3×w_(16a)),    (f×w_(16a), f×w_(16a)), (f×w_(16a), −f×w_(16a)), (f×w_(16a),    −3×w_(16a)), (−f×w_(16a), 3×w_(16a)), (−f×w_(16a), f×w_(16a)),    (−f×w_(16a), −f×w_(16a)), (−f×w_(16a), −3×w_(16a)), (−3×w_(16a),    3×w_(16a)), (−3×w_(16a), f×w_(16a)), (−3×w_(16a), −f×w_(16a)),    (−3×w_(16a), −3×w_(16a))    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, and b3 (0000    to 1111) serve as in-phase component I and orthogonal component Q of    the post-mapping baseband signal. The relationship between the set    of b0, b1, b2, and b3 (0000 to 1111) in 16 QAM and the coordinates    of the signal point is not limited to that illustrated in FIG. 3.

The 16 signal points in FIG. 3 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 15”, and “signal point 16”(because 16 signal points exist, “signal point 1” to “signal point 16”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(16a) is given as follows.

[Mathematical  formula  1] $\begin{matrix}\begin{matrix}{w_{16a} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{16}\; D_{i}^{2}}{16}}}} \\{= \frac{z}{\sqrt{\frac{\begin{matrix}( {{( {3^{2} + 3^{2}} ) \times 4} + {( {f^{2} + f^{2}} ) \times}}  \\ {4 + {( {f^{2} + 3^{2}} ) \times 8}} )\end{matrix}}{16}}}}\end{matrix} & ( {{Equation}\mspace{14mu} 1} )\end{matrix}$

From (Equation 1), an average power of the post-mapping baseband signalis z².

The 16 QAM mapping method is generally called non-uniform 16 QAM.However, in this case, the 16 QAM mapping method is referred to as “16QAM mapping method #1”.

In above description, “f≠3 and f≠1” hold in FIG. 3. In the case that“f=1” is satisfied, the mapping method is referred to as uniform 16 QAM,and is hereinafter referred to as “16 QAM mapping method #0”.

The 16 QAM mapping method will be described below.

FIG. 4 illustrates an example of the 16 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 4, 16 marks “◯” (whitecircle) indicate the 16 QAM signal points, the horizontal axis indicatesthe in-phase component I, and the vertical axis indicates the orthogonalcomponent Q.

In FIG. 4, f₁≠0 (f₁ is a real number greater than 0), f₂>0 (f₂ is a realnumber greater than 0), f₁≠3, f₂≠3, and f₁≠f₂ hold.

In the in-phase I-orthogonal Q plane, coordinates of the 16 signalpoints (in FIG. 4, the mark “◯” indicates the signal point) for 16 QAMare expressed as follows:

-   (3×w_(16b), 3×w_(16b)), (3×w_(16b), f₂×w_(16b)), (3×w_(16b),    −f₂×w_(16b)), (3×w_(16b), −3×w_(16b)), (f₁×w_(16b), 3×w_(16b)),    (f₁×w_(16b), f₂×w_(16b)), (f₁×w_(16b), −f₂×w_(16b)), (f₁×w_(16b),    −3×w_(16b)), (−f₁×w_(16b), 3×w_(16b)), (−f₁×w_(16b), f₂×w_(16b)),    (−f₁×w_(16b), −f₂×w_(16b)), (−f₁×w_(16b), −3×w_(16b)), (−3×w_(16b),    3×w_(16b)), (−3×w_(16b), f₂×w_(16b)), (−3×w_(16b), −f₂×w_(16b)),    (−3×w_(16b), −3×w_(16b)), where w_(16b) is a real number greater    than 0.

In FIG. 4, the bits (input bits) to be transmitted are set to b0, b1,b2, and b3. For example, the bits to be transmitted(b0,b1,b2,b3)=(0,0,0,0) are mapped in signal point H201 of FIG. 4 and(I,Q)=(3×w_(16b), 3×w_(16b)) is obtained, where I and Q are the in-phasecomponent and the orthogonal component of the post-mapping basebandsignal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 16 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3). An example of the relationship betweena set of b0, b1, b2, and b3 (0000 to 1111) and the coordinates of thesignal point is indicated in FIG. 4. FIG. 4 illustrates the values ofthe sets of b0, b1, b2, and b3 (0000 to 1111) immediately below the 16signal points (the marks “◯” in FIG. 4) of 16 QAM:

-   (3×w_(16b), 3×w_(16b)), (3×w_(16b), f₂×w_(16b)), (3×w_(16b),    −f₂×w_(16b)), (3×w_(16b), −3×w_(16b)), (f₁×w_(16b), 3×w_(16b)),    (f₁×w_(16b), f₂×w_(16b)), (f₁×w_(16b), −f₂×w_(16b)), (f₁×w_(16b),    −3×w_(16b)), (f₁×w_(16b), 3×w_(16b)), (−f₁×w_(16b), f₂×w_(16b)),    (−f₁×w_(16b), −f₂×w_(16b)), (−f₁×w_(16b), −3×w_(16b)), (−3×w_(16b),    3×w_(16b)), (−3×w_(16b), f₂×w_(16b)), (−3×w_(16b), −f₂×w_(16b)),    (−3×w_(16b), −3×w_(16b)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, and b3 (0000    to 1111) serve as in-phase component I and orthogonal component Q of    the post-mapping baseband signal. The relationship between the set    of b0, b1, b2, and b3 (0000 to 1111) in 16 QAM and the coordinates    of the signal point is not limited to that illustrated in FIG. 4.

The 16 signal points in FIG. 4 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 15”, and “signal point 16”(because 16 signal points exist, “signal point 1” to “signal point 16”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(16b) is given as follows.

[Mathematical  formula  2] $\begin{matrix}\begin{matrix}{w_{16b} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{16}\; D_{i}^{2}}{16}}}} \\{= \frac{z}{\sqrt{\frac{\begin{matrix}( {{( {3^{2} + 3^{2}} ) \times 4} + {( {f_{1}^{2} + f_{2}^{2}} ) \times}}  \\ {4 + {( {f_{1}^{2} + 3^{2}} ) \times 4} + {( {f_{2}^{2} + 3^{2}} ) \times 4}} )\end{matrix}}{16}}}}\end{matrix} & ( {{Equation}\mspace{14mu} 2} )\end{matrix}$

From (Equation 2), an average power of the post-mapping baseband signalis z².

Hereinafter, the 16 QAM mapping method is referred to as “16 QAM mappingmethod #2”.

The 16 QAM mapping method will be described below.

FIG. 5 illustrates an example of the 16 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 5, 16 marks “◯” (whitecircle) indicate the 16 QAM signal points, the horizontal axis indicatesthe in-phase component I, and the vertical axis indicates the orthogonalcomponent Q.

In FIG. 5, k₁>0 (k₁ is a real number greater than 0), k₂>0 (k₂ is a realnumber greater than 0), k₁≠1, k₂≠1, and k₁≠k₂ hold.

In the in-phase I-orthogonal Q plane, coordinates of the 16 signalpoints (in FIG. 5, the mark “◯” indicates the signal point) for 16 QAMare expressed as follows:

-   (k₁×w_(16c), k₂×w_(16c)), (k₁×w_(16c), 1×w_(16c)), (k₁×w_(16c),    −1×w_(16c)), (k₁×w_(16c), −k₂×w_(16c)), (1×w_(16c), k₂×w_(16c)),    (1×w_(16c), 1×w_(16c)), (1×w_(16c), −1×w_(16c)), (1×w_(16c),    −k₂×w_(16c)), (−1×w_(16c), k₂×w_(16c)), (−1×w_(16c), 1×w_(16c)),    (−1×w_(16c), −1×w_(16c)), (−1×w_(16c), −k₂×w_(16c)), (−k₁×w_(16c),    k₂×w_(16c)), (−k₁×w_(16c), 1×w_(16c)), (−k₁×w_(16c), −1×w_(16c)),    (−k₁×w_(16c), −k₂×w_(16c)), where w_(16c) is a real number greater    than 0.

In FIG. 5, the bits (input bits) to be transmitted are set to b0, b1,b2, and b3. For example, the bits to be transmitted(b0,b1,b2,b3)=(0,0,0,0) are mapped in signal point H301 of FIG. 5 and(I,Q)=(k₁×w_(16c), k₂×w_(16c)) is obtained, where I and Q are thein-phase component and the orthogonal component of the post-mappingbaseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 16 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3). An example of the relationship betweena set of b0, b1, b2, and b3 (0000 to 1111) and the coordinates of thesignal point is indicated in FIG. 5. FIG. 5 illustrates the values ofthe sets of b0, b1, b2, and b3 (0000 to 1111) immediately below the 16signal points (the marks “◯” in FIG. 5) of 16 QAM:

-   (k₁×w_(16c), k₂×w_(16c)), (k₁×w_(16c), 1×w_(16c)), (k₁×w_(16c),    −1×w_(16c)), (k₁×w_(16c), −k₂×w_(16c)), (1×w_(16c), k₂×w_(16c)),    (1×w_(16c), 1×w_(16c)), (1×w_(16c), −1×w_(16c)), (1×w_(16c),    −k₂×w_(16c)), (−1×w_(16c), k₂×w_(16c)), (−1×w_(16c), 1×w_(16c)),    (−1×w_(16c), −1×w_(16c)), (−1×w_(16c), −k₂×w_(16c)), (−k₁×w_(16c),    k₂×w_(16c)), (−k₁×w_(16c), 1×w_(16c)), (−k₁×w₁₆, −1×w_(16c)),    (−k₁×w_(16c), −k₂×w_(16c)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, and b3 (0000    to 1111) serve as in-phase component I and orthogonal component Q of    the post-mapping baseband signal. The relationship between the set    of b0, b1, b2, and b3 (0000 to 1111) in 16 QAM and the coordinates    of the signal point is not limited to that illustrated in FIG. 5.

The 16 signal points in FIG. 5 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 15”, and “signal point 16”(because 16 signal points exist, “signal point 1” to “signal point 16”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(16c) is given as follows.

[Mathematical  formula  3] $\begin{matrix}\begin{matrix}{w_{16c} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{16}\; D_{i}^{2}}{16}}}} \\{= \frac{z}{\sqrt{\frac{\begin{matrix}( {{( {1^{2} + 1^{2}} ) \times 4} + {( {k_{1}^{2} + k_{2}^{2}} ) \times}}  \\ {4 + {( {k_{1}^{2} + 1^{2}} ) \times 4} + {( {k_{2}^{2} + 1^{2}} ) \times 4}} )\end{matrix}}{16}}}}\end{matrix} & ( {{Equation}\mspace{14mu} 3} )\end{matrix}$

From (Equation 3), an average power of the post-mapping baseband signalis z².

Hereinafter, the 16 QAM mapping method is referred to as “16 QAM mappingmethod #3”.

The 64 QAM mapping method will be described below.

FIG. 6 illustrates an example of a 64 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 6, 64 marks “◯” (whitecircle) indicate the 64 QAM signal points, the horizontal axis indicatesthe in-phase component I, and the vertical axis indicates the orthogonalcomponent Q.

In FIG. 6,

-   g₁>0 (g₁ is a real number greater than 0) and g₂>0 (g₂ is a real    number greater than 0) and g₃>0 (g₃ is a real number greater than 0)    hold,-   {{g₁≠7 and g₂≠7 and g₃≠7} holds}, and-   {{(g₁, g₂, g₃)≠(1,3,5) and (g₁, g₂, g₃)≠(1,5,3) and (g₁, g₂,    g₃)≠(3,1,5) and (g₁, g₂, g₃)≠(3,5,1) and (g₁, g₂, g₃)≠(5,1,3) and    (g₁, g₂, g₃)≠(5,3,1)} holds}, and-   {{g₁≠g₂ and g₁≠g₃ and g₂≠g₃} holds}.

In the in-phase I-orthogonal Q plane, coordinates of the 64 signalpoints (in FIG. 6, the mark “◯” indicates the signal point) for 64 QAMare expressed as follows:

-   (7×w_(64a), 7×w_(64a)), (7×w_(64a), g₃×w_(64a)), (7×w_(64a),    g₂×w_(64a)), (7×w_(64a), g₁×w_(64a)), (7×w_(64a), −g₁×w_(64a)),    (7×w_(64a), −g₂×w_(64a)), (7×w_(64a), −g₃×w_(64a)), (7×w_(64a),    −7×w_(64a)),-   (g₃×w_(64a), 7×w_(64a)), (g₃×w_(64a), g₃×w_(64a)), (g₃×w_(64a),    g₂×w_(64a)), (g₃×w_(64a), g₁×w_(64a)), (g₃×w_(64a), −g₁×w_(64a)),    (g₃×w_(64a), g₂×w_(64a)), (g₃×w_(64a), −g₃×w_(64a)), (g₃×w_(64a),    −7×w_(64a)),-   (g₂×w_(64a), 7×w_(64a)), (g₂×w_(64a), g₃×w_(64a)), (g₂×w_(64a),    g₂×w_(64a)), (g₂×w_(64a), g₁×w_(64a)), (g₂×w_(64a), −g₁×w_(64a)),    (g₂×w_(64a), g₂×w_(64a)), (g₂×w_(64a), −g₃×w_(64a)), (g₂×w_(64a),    −7×w_(64a)),-   (g₁×w_(64a), 7×w_(64a)), (g₁×w_(64a), g₃×w_(64a)), (g₁×w_(64a),    g₂×w_(64a)), (g₁×w_(64a), g₁×w_(64a)), (g₁×w_(64a), −g₁×_(64a)),    (g₁×w_(64a), −g₂×w_(64a)), (g₁×w_(64a), −g₃×w_(64a)), (g₁×w_(64a),    −7×w_(64a)),-   (−g₁×_(64a), 7×w_(64a)), (−g₁×w_(64a), g₃×w_(64a)), (−g₁×w_(64a),    g₂×w_(64a)), (−g₁×w_(64a), g₁×w_(64a)), (−g₁×w_(64a), −g₁×w_(64a)),    (−g₁×w_(64a), −g₂×w_(64a)), (−g₁×w_(64a), −g₃×w_(64a)),    (−g₁×w_(64a), −7×w_(64a)),-   (−g₂×w_(64a), 7×w_(64a)), (−g₂×w_(64a), g₃×w_(64a)), (−g₂×w_(64a),    g₂×w_(64a)), (−g₂×w_(64a), g₁×w_(64a)), (−g₂×w_(64a), −g₁×w_(64a)),    (−g₂×w_(64a), −g₂×w_(64a)), (−g₂×w_(64a), −g₃×w_(64a)),    (−g₂×w_(64a), −7×w_(64a)),-   (−g₃×w_(64a), 7×w_(64a)), (−g₃×w_(64a), g₃×w_(64a)), (−g₃×w_(64a),    g₂×w_(64a)), (−g₃×w_(64a), g₁×w_(64a)), (−g₃×w_(64a), −g₁×w_(64a)),    (−g₃×w_(64a), −g₂×w_(64a)), (−g₃×w_(64a), −g₃×w_(64a)),    (−g₃×w_(64a), −7×w_(64a)),-   (−7×w_(64a), 7×w_(64a)), (−7×w_(64a), g₃×w_(64a)), (−7×w_(64a),    g₂×w_(64a)), (−7×w_(64a), g₁×w_(64a)), (−7×w_(64a), −g₁×w_(64a)),    (−7×w_(64a), −g₂×w_(64a)), (−7×w_(64a), −g₃×w_(64a)), (−7×w_(64a),    −7×w_(64a)), where w_(64a) is a real number greater than 0.

In FIG. 6, the bits (input bits) to be transmitted are set to b0, b1,b2, b3, b4, and b5. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5)=(0,0,0,0,0,0) are mapped in signal point H401 ofFIG. 6 and (I,Q)=(7×w_(64a), 7×w_(64a)) is obtained, where I and Q arethe in-phase component and the orthogonal component of the post-mappingbaseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 64 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5). An example of the relationshipbetween a set of b0, b1, b2, b3, b4, and b5 (000000 to 111111) and thecoordinates of the signal point is indicated in FIG. 6. FIG. 6illustrates the values of the sets of b0, b1, b2, b3, b4, and b5 (000000to 111111) immediately below the 64 signal points (the marks “◯” in FIG.6) of 64 QAM:

-   (7×w_(64a), 7×w_(64a)), (7×w_(64a), g₃×w_(64a)), (7×w_(64a),    g₂×w_(64a)), (7×w_(64a), g₁×w_(64a)), (7×w_(64a), −g₁×w_(64a)),    (7×w_(64a), −g₂×w_(64a)), (7×w_(64a), −g₃×w_(64a)), (7×w_(64a),    −7×w_(64a)),-   (g₃×w_(64a), 7×w_(64a)), (g₃×w_(64a), g₃×w_(64a)), (g₃×w_(64a),    g₂×w_(64a)), (g₃×w_(64a), g₁×w_(64a)), (g₃×w_(64a), −g₁×w_(64a)),    (g₃×w_(64a), −g₂×w_(64a)), (g₃×w_(64a), −g₃×w_(64a)), (g₃×w_(64a),    −7×w_(64a)),-   (g₂×w_(64a), 7×w_(64a)), (g₂×w_(64a), g₃×w_(64a)), (g₂×w_(64a),    g₂×w_(64a)), (g₂×w_(64a), g₁×w_(64a)), (g₂×w_(64a), −g₁×w_(64a)),    (g₂×w_(64a), −g₂×w_(64a)), (g₂×w_(64a), −g₃×w_(64a)), (g₂×w_(64a),    −7×w_(64a)),-   (g₁×w_(64a), 7×w_(64a)), (g₁×w_(64a), g₃×w_(64a)), (g₁×w_(64a),    g₂×w_(64a)), (g₁×w_(64a), g₁×w_(64a)), (g₁×w_(64a), −g₁×w_(64a)),    (g₁×w_(64a), −g₂×w_(64a)), (g₁×w_(64a), −g₃×w_(64a)), (g₁×w_(64a),    −7×w_(64a)),-   (−g₁×w_(64a), 7×w_(64a)), (−g₁×w_(64a), g₃×w_(64a)), (−g₁×w_(64a),    g₂×w_(64a)), (−g₁×w_(64a), g₁×w_(64a)), (−g₁×w_(64a), −g₁×w_(64a)),    (−g₁×w_(64a), −g₂×w_(64a)), (−g₁×w_(64a), −g₃×w_(64a)),    (−g₁×w_(64a), −7×w_(64a)),-   (−g₂×w_(64a), 7×w_(64a)), (−g₂×w_(64a), g₃×w_(64a)), (−g₂×w_(64a),    g₂×w_(64a)), (−g₂×w_(64a), g₁×w_(64a)), (−g₂×w_(64a), −g₁×w_(64a)),    (−g₂×w_(64a), −g₂×w_(64a)), (−g₂×w_(64a), −g₃×w_(64a)),    (−g₂×w_(64a), −7×w_(64a)),-   (−g₃×w_(64a), 7×w_(64a)), (−g₃×w_(64a), g₃×w_(64a)), (−g₃×w_(64a),    g₂×w_(64a)), (−g₃×w_(64a), g₁×w_(64a)), (−g₃×w_(64a), −g₁×w_(64a)),    (−g₃×w_(64a), −g₂×w_(64a)), (−g₃×w_(64a), −g₃×w_(64a)),    (−g₃×w_(64a), −7×w_(64a)),-   (−7×w_(64a), 7×w_(64a)), (−7×w_(64a), g₃×w_(64a)), (−7×w_(64a),    g₂×w_(64a)), (−7×w_(64a), g₁×w_(64a)), (−7×w_(64a), −g₁×w_(64a)),    (−7×w_(64a), −g₂×w_(64a)), (−7×w_(64a), −g₃×w_(64a)), (−7×w_(64a),    −7×w_(64a)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, b3, b4, and b5    (000000 to 111111) serve as in-phase component I and orthogonal    component Q of the post-mapping baseband signal. The relationship    between the set of b0, b1, b2, b3, b4, and b5 (000000 to 111111) in    64 QAM and the coordinates of the signal point is not limited to    that illustrated in FIG. 6.

The 64 signal points in FIG. 6 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 63”, and “signal point 64”(because 64 signal points exist, “signal point 1” to “signal point 64”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(64a) is given as follows.

[Mathematical  formula  4] $\begin{matrix}{w_{64a} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{64}\; D_{i}^{2}}{64}}}} & ( {{Equation}\mspace{14mu} 4} )\end{matrix}$

From (Equation 4), an average power of the post-mapping baseband signalis z².

The 64 QAM mapping method is generally called non-uniform 64 QAM.However, in this case, the 64 QAM mapping method is referred to as “64QAM mapping method #1”.

The mapping method in the case that “(g₁, g₂, g₃) (1,3,5)” is satisfiedin the above description is generally referred to as uniform 64 QAM, andis hereinafter referred to as “64 QAM mapping method #0”.

FIG. 7 illustrates an example of the 64 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 7, 64 marks “◯” (whitecircle) indicate the 64 QAM signal points, the horizontal axis indicatesthe in-phase component I, and the vertical axis indicates the orthogonalcomponent Q.

In FIG. 7,

-   g₁>0 (g₁ is a real number greater than 0) and g₂>0 (g₂ is a real    number greater than 0) and g₃>0 (g₃ is a real number greater than 0)    and g₄>0 (g₄ is a real number greater than 0) and g₅>0 (g₅ is a real    number greater than 0) and g₆>0 (g₆ is a real number greater than 0)    hold, and-   {g₁≠7 and g₂≠7 and g₃≠7 and g₁≠g₂ and g₁≠g₃ and g₂≠g₃} and-   {g₄≠7 and g₅≠7 and g₆≠7 and g₄≠g₅ and g₄≠g₆ and g₅≠g₆} and-   {{g₁≠g₄ or g₂≠g₅ or g₃≠g₆} holds} hold.

In the in-phase I-orthogonal Q plane, coordinates of the 64 signalpoints (in FIG. 7, the mark “◯” indicates the signal point) for 64 QAMare expressed as follows:

-   (7×w_(64b), 7×w_(64b)), (7×w_(64b), g₆×w_(64b)), (7×w_(64b),    g₅×w_(64b)), (7×w_(64b), g₄×w_(64b)), (₄×w_(64b)), (7×w_(64b),    −g₅×w_(64b)), (₆×w_(64b)), (7×w_(64b), −7×w_(64b)),-   (g₃×w_(64b), 7×w_(64b)), (g₃×w_(64b), g₆×w_(64b)), (g₃×w_(64b),    g₅×w_(64b)), (g₃×w_(64b), g₄×w_(64b)), (g₃×w_(64b), −g₄×w_(64b)),    (g₃×w_(64b), −g₅×w_(64b)), (g₃×w_(64b), −g₆×w_(64b)), (g₃×w_(64b),    −7×w_(64b)),-   (g₂×w_(64b), 7×w_(64b)), (g₂×w_(64b), g₆×w_(64b)), (g₂×w_(64b),    g₅×w_(64b)), (g₂×w_(64b), g₄×w_(64b)), (g₂×w_(64b), −g₄×w_(64b)),    (g₂×w_(64b), −g₅×w_(64b)), (g₂×w_(64b), −g₆×w_(64b)), (g₂×w_(64b),    −7×w_(64b)),-   (g₁×w_(64b), 7×w_(64b)), (g₁×w_(64b), g₆×w_(64b)), (g₁×w_(64b),    g₅×w_(64b)), (g₁×w_(64b), g₄×w_(64b)), (g₁×w_(64b), −g₄×w_(64b)),    (g₁×w_(64b), −g₅×w_(64b)), (g₁×w_(64b), −g₆×w_(64b)), (g₁×w_(64b),    −7×w_(64b)),-   (−g₁×w_(64b), 7×w_(64b)), (−g₁×w_(64b), g₆×w_(64b)), (−g₁×w_(64b),    g₅×w_(64b)), (−g₁×w_(64b), g₄×w_(64b)), (−g₁×w_(64b), −g₄×w_(64b)),    (−g₁×w_(64b), −g₅×w_(64b)), (−g₁×w_(64b), −g₆×w_(64b)),    (−g₁×w_(64b), −7×w_(64b)),-   (−g₂×w_(64b), 7×w_(64b)), (−g₂×w_(64b), g₆×w_(64b)), (−g₂×w_(64b),    g₅×w_(64b)), (−g₂×w_(64b), g₄×w_(64b)), (−g₂×w_(64b), −g₄×w_(64b)),    (−g₂×w_(64b), −g₅×w_(64b)), (−g₂×w_(64b), −g₆×w_(64b)),    (−g₂×w_(64b), −7×w_(64b)),-   (−g₃×w_(64b), 7×w_(64b)), (−g₃×w_(64b), g₆×w_(64b)), (−g₃×w_(64b),    g₅×w_(64b)), (−g₃×w_(64b), g₄×w_(64b)), (−g₃×w_(64b), −g₄×w_(64b)),    (−g₃×w_(64b), −g₅×w_(64b)), (−g₃×w_(64b), −g₆×w_(64b)),    (−g₃×w_(64b), −7×w_(64b)),-   (−7×w_(64b), 7×w_(64b)), (−7×w_(64b), g₆×w_(64b)), (−7×w_(64b),    g₅×w_(64b)), (−7×w_(64b), g₄×w_(64b)), (−₄×w_(64b)), (−7×w_(64b),    −g₅×w_(64b)), (−7×w_(64b), −g₆×w_(64b)), (−7×w_(64b), −7×w_(64b)),    where w_(64b) is a real number greater than 0.

In FIG. 7, the bits (input bits) to be transmitted are set to b0, b1,b2, b3, b4, and b5. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5)=(0,0,0,0,0,0) are mapped in signal point H501 ofFIG. 7 and (I,Q)=(7×w_(64b), 7×w_(64b)) is obtained, where I and Q arethe in-phase component and the orthogonal component of the post-mappingbaseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 64 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5). An example of the relationshipbetween a set of b0, b1, b2, b3, b4, and b5 (000000 to 111111) and thecoordinates of the signal point is indicated in FIG. 7. FIG. 7illustrates the values of the sets of b0, b1, b2, b3, b4, and b5 (000000to 111111) immediately below the 64 signal points (the marks “◯” in FIG.7) of 64 QAM:

-   (7×w_(64b), 7×w_(64b)), (7×w_(64b), g₆×w_(64b)), (7×w_(64b),    g₅×w_(64b)), (7×w_(64b), g₄×w_(64b)), (7×w_(64b), −g₄×w_(64b)),    (7×w_(64b), −g₅×w_(64b)), (7×w_(64b), −g₆×w_(64b)), (7×w_(64b),    −7×w_(64b)),-   (g₃×w_(64b), 7×w_(64b)), (g₃×w_(64b), g₆×w_(64b)), (g₃×w_(64b),    g₅×w_(64b)), (g₃×w_(64b), g₄×w_(64b)), (g₃×w_(64b), −g₄×w_(64b)),    (g₃×w_(64b), −g₅×w_(64b)), (g₃×w_(64b), −g₆×w_(64b)), (g₃×w_(64b),    −7×w_(64b)),-   (g₂×w_(64b), 7×w_(64b)), (g₂×w_(64b), g₆×w_(64b)), (g₂×w_(64b),    g₅×w_(64b)), (g₂×w_(64b), g₄×w_(64b)), (g₂×w_(64b), −g₄×w_(64b)),    (g₂×w_(64b), −g₅×w_(64b)), (g₂×w_(64b), −g₆×w_(64b)), (g₂×w_(64b),    −7×w_(64b)),-   (g₁×w_(64b), 7×w_(64b)), (g₁×w_(64b), g₆×w_(64b)), (g₁×w_(64b),    g₅×w_(64b)), (g₁×w_(64b), g₄×w_(64b)), (g₁×w_(64b), −g₄×w_(64b)),    (g₁×w_(64b), −g₅×w_(64b)), (g₁×w_(64b), −g₆×w_(64b)), (g₁×w_(64b),    −7×w_(64b)),-   (−g₁×w_(64b), 7×w_(64b)), (−g₁×w_(64b), g₆×w_(64b)), (−g₁×w_(64b),    g₅×w_(64b)), (−g₁×w_(64b), g₄×w_(64b)), (−g₁×w_(64b), −g₄×w_(64b)),    (−g₁×w_(64b), −g₅×w_(64b)), (−g₁×w_(64b), −g₆×w_(64b)),    (−g₁×w_(64b), −7×w_(64b)),-   (−g₂×w_(64b), 7×w_(64b)), (−g₂×w_(64b), g₆×w_(64b)), (−g₂×w_(64b),    g₅×w_(64b)), (−g₂×w_(64b), g₄×w_(64b)), (−g₂×w_(64b), −g₄×w_(64b)),    (−g₂×w_(64b), −g₅×w_(64b)), (−g₂×w_(64b), −g₅×w_(64b)),    (−g₂×w_(64b), −7×w_(64b)),-   (−g₃×w_(64b), 7×w_(64b)), (−g₃×w_(64b), g₆×w_(64b)), (−g₃×w_(64b),    g₅×w_(64b)), (−g₃×w_(64b), g₄×w_(64b)), (−g₃×w_(64b), −g₄×w_(64b)),    (−g₃×w_(64b), −g₅×w_(64b)), (−g₃×w_(64b), −g₆×w_(64b)),    (−g₃×w_(64b), −7×w_(64b)),-   (−7×w_(64b), 7×w_(64b)), (−7×w_(64b), g₆×w_(64b)), (−7×w_(64b),    g₅×w_(64b)), (−7×w_(64b), g₄×w_(64b)), (−7×w_(64b), −g₄×w_(64b)),    (−7×w_(64b), −g₅×w_(64b)), (−7×w_(64b), −g₆×w_(64b)), (−7×w_(64b),    −7×w_(64b)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, b3, b4, and b5    (000000 to 111111) serve as in-phase component I and orthogonal    component Q of the post-mapping baseband signal. The relationship    between the set of b0, b1, b2, b3, b4, and b5 (000000 to 111111) in    64 QAM and the coordinates of the signal point is not limited to    that illustrated in FIG. 7.

The 64 signal points in FIG. 7 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 63”, and “signal point 64”(because 64 signal points exist, “signal point 1” to “signal point 64”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(64b) is given as follows.

[Mathematical  formula  5] $\begin{matrix}{w_{64b} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{64}\; D_{i}^{2}}{64}}}} & ( {{Equation}\mspace{14mu} 5} )\end{matrix}$

From (Equation 5), an average power of the post-mapping baseband signalis z².

Hereinafter, the 64 QAM mapping method is referred to as “64 QAM mappingmethod #2”.

FIG. 8 illustrates an example of the 64 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 8, 64 marks “◯” (whitecircle) indicate the 64 QAM signal points, the horizontal axis indicatesthe in-phase component I, and the vertical axis indicates the orthogonalcomponent Q.

In FIG. 8,

-   “m₁>0 (m₁ is a real number greater than 0) and m₂>0 (m₂ is a real    number greater than 0) and m₃>0 (m₃ is a real number greater than 0)    and m₄>0 (m₄ is a real number greater than 0) and m₅>0 (m₅ is a real    number greater than 0) and m₆>0 (m₆ is a real number greater than 0)    and m₇>0 (m₇ is a real number greater than 0) and m₈>0 (m₈ is a real    number greater than 0) hold, and-   {m₁≠m₂ and m₁≠m₃ and m₁≠m₄ and m₂≠m₃ and m₂≠m₄ and m₃≠m₄} and-   {m₅≠m₆ and m₅≠m₇ and m₅≠m₈ and m₆≠m₇ and m₆≠m₈ and m₇≠m₈} and-   {m₁≠m₅ or m₂≠m₆ or m₃≠m₇ or m₄≠m₈ holds} hold.”

or

“m₁>0 (m₁ is a real number greater than 0) and m₂>0 (m₂ is a real numbergreater than 0) and m₃>0 (m₃ is a real number greater than 0) and m₄>0(m₄ is a real number greater than 0) and m₅>0 (m₅ is a real numbergreater than 0) and m₆>0 (m₆ is a real number greater than 0) and m₇>0(m₇ is a real number greater than 0) and m₈>0 (m₈ is a real numbergreater than 0) hold, and

-   {m₁≠m₂ and m₁≠m₃ and m₁≠m₄ and m₂≠m₃ and m₂≠m₄ and m₃≠m₄} and-   {m₅≠m₆ and m₅≠m₇ and m₅≠m₈ and m₆≠m₇ and m₆≠m₈ and m₇≠m₈} and-   {m₁≠m₅ or m₂≠m₆ or m₃≠m₇ or m₄≠m₈ holds} and-   {m₁≠m₅ or m₂≠m₆ or m₃≠m₇ or m₄≠m₈ holds} hold.”

In the in-phase I-orthogonal Q plane, coordinates of the 64 signalpoints (in FIG. 8, the mark “◯” indicates the signal point) for 64 QAMare expressed as follows:

-   (m₄×w_(64c), m₈×w_(64c)), (m₄×w_(64c), m₇×w_(64c)), (m₄×w_(64c),    m₆×w_(64c)), (m₄×w_(64c), m₅×w_(64c)), (m₄×w_(64c), −m₅×w_(64c)),    (m₄×w_(64c), −m₆×w_(64c)), (m₄×w_(64c), −m₇×w_(64c)), (m₄×w_(64c),    −m₈×w_(64c)),-   (m₃×w_(64c), m₈×w_(64c)), (m₃×w_(64c), m₇×w_(64c)), (m₃×w_(64c),    m₆×w_(64c)), (m₃×w_(64c), m₅×w_(64c)), (m₃×w_(64c), −m₅×w_(64c)),    (m₃×w_(64c), −m₆×w_(64c)), (m₃×w_(64c), −m₇×w_(64c)), (m₃×w_(64c),    −m₈×w_(64c)),-   (m₂×w_(64c), m₈×w_(64c)), (m₂×w_(64c), m₇×w_(64c)), (m₂×w_(64c),    m₆×w_(64c)), (m₂×w_(64c), m₅×w_(64c)), (m₂×w_(64c), −m₅×w_(64c)),    (m₂×w_(64c), −m₆×w_(64c)), (m₂×w_(64c), −m₇×w_(64c)), (m₂×w_(64c),    −m₈×w_(64c)),-   (m₁×w_(64c), m₈×w_(64c)), (m₁×w_(64c), m₇×w_(64c)), (m₁×w_(64c),    m₆×w_(64c)), (m₁×w_(64c), m₅×w_(64c)), (m₁×w_(64c), −m₅×w_(64c)),    (m₁×w_(64c), −m₆×w_(64c)), (m₁×w_(64c), −m₇×w_(64c)), (m₁×w_(64c),    −m₈×w_(64c)),-   (−m₁×w_(64c), m₈×w_(64c)), (−m₁×w_(64c), m₇×w_(64c)), (−m₁×w_(64c),    m₆×w_(64c)), (−m₁×w_(64c), m₅×w_(64c)), (−m₁×w_(64c), m₅×w_(64c)),    (−m₁×w_(64c), −m₆×w_(64c)), (−m₁×w_(64c), −m₇×w_(64c)),    (−m₁×w_(64c), −m₈×w_(64c)),-   (−m₂×w_(64c), m₈×w_(64c)), (−m₂×w_(64c), m₇×w_(64c)), (−m₂×w_(64c),    m₆×w_(64c)), (−m₂×w_(64c), m₅×w_(64c)), (−m₂×w_(64c), −m ₅×w_(64c)),    (−m₂×w_(64c), −m₆×w_(64c)), (−m₂×w_(64c), −m₇×w_(64c)),    (−m₂×w_(64c), −m₈×w_(64c)),-   (−m₃×w_(64c), m₈×w_(64c)), (−m₃×w_(64c), m₇×w_(64c)), (−m₃×w_(64c),    m₆×w_(64c)), (−m₃×w_(64c), m₅×w_(64c)), (−m₃×w_(64c), m₅×w_(64c)),    (−m₃×w_(64c), −m₆×w_(64c)), (−m₃×w_(64c), −m₇×w_(64c)),    (−m₃×w_(64c), −m₈×w_(64c)),-   (−m₄×w_(64c), m₈×w_(64c)), (−m₄×w_(64c), m₇×w_(64c)), (−m₄×w_(64c),    m₆×w_(64c)), (−m₄×w_(64c), m₅×w_(64c)), (−m₄×w_(64c), −m₅×w_(64c)),    (−m₄×w_(64c), −m₆×w_(64c)), (−m₄×w_(64c), −m₇×w_(64c)),    (−m₄×w_(64c), −m₈×w_(64c)), where w_(64c) is a real number greater    than 0.

In FIG. 8, the bits (input bits) to be transmitted are set to b0, b1,b2, b3, b4, and b5. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5)=(0,0,0,0,0,0) are mapped in signal point H601 ofFIG. 8 and (I,Q)=(m₄×w_(64c), m₈×w_(64c)) is obtained, where I and Q arethe in-phase component and the orthogonal component of the post-mappingbaseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 64 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5). An example of the relationshipbetween a set of b0, b1, b2, b3, b4, and b5 (000000 to 111111) and thecoordinates of the signal point is indicated in FIG. 8. The values ofthe sets of b0, b1, b2, b3, b4, and b5 (000000 to 111111) are indicatedimmediately below the 64 signal points (the marks “◯” in FIG. 8) of 64QAM:

-   (m₄×w_(64c), m₈×w_(64c)), (m₄×w_(64c), m₇×w_(64c)), (m₄×w_(64c),    m₆×w_(64c)), (m₄×w_(64c), m₅×w_(64c)), (m₄×w_(64c), −m₅×w_(64c)),    (m₄×w_(64c), −m₆×w_(64c)), (m₄×w_(64c), −m₇×w_(64c)), (m₄×w_(64c),    −m₈×w_(64c)),-   (m₃×w_(64c), m₈×w_(64c)), (m₃×w_(64c), m₇×w_(64c)), (m₃×w_(64c),    m₆×w_(64c)), (m₃×w_(64c), m₅×w_(64c)), (m₃×w_(64c), −m₅×w_(64c)),    (m₃×w_(64c), −m₆×w_(64c)), (m₃×w_(64c), −m₇×w_(64c)), (m₃×w_(64c),    −m₈×w_(64c)),-   (m₂×w_(64c), m₈×w_(64c)), (m₂×w_(64c), m₇×w_(64c)), (m₂×w_(64c),    m₆×w_(64c)), (m₂×w_(64c), m₅×w_(64c)), (m₂×w_(64c), −m₅×w_(64c)),    (m₂×w_(64c), −m₆×w_(64c)), (m₂×w_(64c), −m₇×w_(64c)), (m₂×w_(64c),    −m₈×w_(64c)),-   (m₁×w_(64c), m₈×w_(64c)), (m₁×w_(64c), m₇×w_(64c)), (m₁×w_(64c),    m₆×w_(64c)), (m₁×w_(64c), m₅×w_(64c)), (m₁×w_(64c), −m₅×w_(64c)),    (m₁×w_(64c), −m₆×w_(64c)), (m₁×w_(64c), −m₇×w_(64c)), (m₁×w_(64c),    −m₈×w_(64c)),-   (−m₁×w_(64c), m₈×w_(64c)), (−m₁×w_(64c), m₇×w_(64c)), (−m₁×w_(64c),    m₆×w_(64c)), (−m₁×w_(64c), m₅×w_(64c)), (−m₁×w_(64c), −m₅×w_(64c)),    (−m₁×w_(64c), −m₆×w_(64c)), (−m₁×w_(64c), −m₇×w_(64c)),    (−m₁×w_(64c), −m₈×w_(64c)),-   (−m₂×w_(64c), m₈×w_(64c)), (−m₂×w_(64c), m₇×w_(64c)), (−m₂×w_(64c),    m₆×w_(64c)), (−m₂×w_(64c), m₅×w_(64c)), (−m₂×w_(64c), −m₅×w_(64c)),    (−m₂×w_(64c), −m₆×w_(64c)), (−m₂×w_(64c), −m₇×w_(64c)),    (−m₂×w_(64c), −m₈×w_(64c)),-   (−m₃×w_(64c), m₈×w_(64c)), (−m₃×w_(64c), m₇×w_(64c)), (−m₃×w_(64c),    m₆×w_(64c)), (−m₃×w_(64c), m₅×w_(64c)), (−m₃×w_(64c), −m₅×w_(64c)),    (−m₃×w_(64c), −m₆×w_(64c)), (−m₃×w_(64c), −m₇×w_(64c)),    (−m₃×w_(64c), −m₈×w_(64c)),-   (−m₄×w_(64c), m₈×w_(64c)), (−m₄×w_(64c), m₇×w_(64c)), (−m₄×w_(64c),    m₆×w_(64c)), (−m₄×w_(64c), m₅×w_(64c)), (−m₄×w_(64c), −m₅×w_(64c)),    (−m₄×w_(64c), −m₆×w_(64c)), (−m₄×w_(64c), −m₇×w_(64c)),    (−m₄×w_(64c), −m₈×w_(64c)).

The coordinates in the in-phase I-orthogonal Q plane of the signal point(“◯”) immediately above the set of b0, b1, b2, b3, b4, and b5 (000000 to111111) serve as in-phase component I and orthogonal component Q of thepost-mapping baseband signal. The relationship between the set of b0,b1, b2, b3, b4, and b5 (000000 to 111111) in 64 QAM and the coordinatesof the signal point is not limited to that illustrated in FIG. 8.

The 64 signal points in FIG. 8 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 63”, and “signal point 64”(because 64 signal points exist, “signal point 1” to “signal point 64”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(64c) is given as follows.

[Mathematical  formula  6] $\begin{matrix}{w_{64c} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{64}\; D_{i}^{2}}{64}}}} & ( {{Equation}\mspace{14mu} 6} )\end{matrix}$

From (Equation 6), an average power of the post-mapping baseband signalis z².

Hereinafter, the 64 QAM mapping method is referred to as “64 QAM mappingmethod #3”.

The 256 QAM mapping method will be described below.

FIG. 9 illustrates an example of a 256 QAM signal point arrangement inthe in-phase I-orthogonal Q plane. In FIG. 9, 256 marks “◯” (whitecircle) indicate the 256 QAM signal points, the horizontal axisindicates the in-phase component I, and the vertical axis indicates theorthogonal component Q.

In FIG. 9, h₁>0 (h₁ is a real number greater than 0) and h₂>0 (h₂ is areal number greater than 0) and h₃>0 (h₃ is a real number greater than0) and h₄>0 (h₄ is a real number greater than 0) and h₅>0 (h₅ is a realnumber greater than 0) and h₆>0 (h₆ is a real number greater than 0) andh₇>0 (h₇ is a real number greater than 0) hold,

-   {{h₁≠15 and h₂≠15 and h₃ ≠15 and h₄≠15 and h₅≠15 and h₆≠15 and    h₇≠15} holds},-   and-   {{a1 is an integer of 1 to 7 and a2 is an integer of 1 to 7 and a3    is an integer of 1 to 7 and a4 is an integer of 1 to 7 and a5 is an    integer of 1 to 7 and a6 is an integer of 1 to 7 and a7 is an    integer of 1 to 7} holds, and    (h_(a1),h_(a2),h_(a3),h_(a4),h_(a5),h_(a6),h_(a7))≠(1,3,5,7,9,11,13)    holds when {ax≠ay holds in all integers x and integers y} when {x is    an integer of 1 to 7 and y is an integer of 1 to 7 and x≠y} holds},-   and {{h₁≠h₂ and h₁≠h₃ and h₁≠h₄ and h₁≠h₅ and h₁≠h₆ and h₁≠h₇-   and h₂≠h₃ and h₂≠h₄ and h₂≠h₅ and h₂≠h₆ and h₂≠h₇-   and h₃≠h₄ and h₃≠h₅ and h₃≠h₆ and h₃≠h₇-   and h₄≠h₅ and ha ₄≠h₆ and h₄≠h₇-   and h₅≠h₆ and h₅≠h₇-   and h₆≠h₇} holds}.

In the in-phase I-orthogonal Q plane, coordinates of the 256 signalpoints (in FIG. 9, the mark “◯” indicates the signal point) for 256 QAMare expressed as follows:

-   (15×w_(256a), 15×w_(256a)), (15×w_(256a), h₇×w_(256a)),    (15×w_(256a), h₆×w_(256a)), (15×w_(256a), h₅×w_(256a)),    (15×w_(256a), h₄×w_(256a)), (15×w_(256a), h₃×w_(256a)),    (15×w_(256a), h₂×w_(256a)), (15×w_(256a), h₁×w_(256a)),    (15×w_(256a), −15×w_(256a)), (15×w_(256a), −h₇×w_(256a)),    (15×w_(256a), −h₆×w_(256a)), (15×w_(256a), −h₅×w_(256a)),    (15×w_(256a), −h₄×w_(256a)), (15×w_(256a), −h₃×w_(256a)),    (15×w_(256a), −h₂×w_(256a)), (15×w_(256a), −h₁×w_(256a)),-   (h₇×w_(256a), 15×w_(256a)), (h₇×w_(256a), h₇×w_(256a)),    (h₇×w_(256a), h₆×w_(256a)), (h₇×w_(256a), h₅×w_(256a)),    (h₇×w_(256a), h₄×w_(256a)), (h₇×w_(256a), h₃×w_(256a)),    (h₇×w_(256a), h₂×w_(256a)), (h₇×w_(256a), h₁×w_(256a)),    (h₇×w_(256a), −15×w_(256a)), (h₇×w_(256a), −h₇×w_(256a)),    (h₇×w_(256a), −h₆×w_(256a)), (h₇×w_(256a), −h₅×w_(256a)),    (h₇×w_(256a), −h₄×w_(256a)), (h₇×w_(256a), −h₃×w_(256a)),    (h₇×w_(256a), −h₂×w_(256a)), (h₇×w_(256a), −h₁×w_(256a)),-   (h₆×w_(256a), 15×w_(256a)), (h₆×w_(256a), h₇×w_(256a)),    (h₆×w_(256a), h₆×w_(256a)), (h₆×w_(256a), h₅×w_(256a)),    (h₆×w_(256a), h₄×w_(256a)), (h₆×w_(256a), h₃×w_(256a)),    (h₆×w_(256a), h₂×w_(256a)), (h₆×w_(256a), h₁×w_(256a)),    (h₆×w_(256a), −15×w_(256a)), (h₆×w_(256a), −h₇×w_(256a)),    (h₆×w_(256a), −h₆×w_(256a)), (h₆×w_(256a), −h₅×w_(256a)),    (h₆×w_(256a), −h₄×w_(256a)), (h₆×w_(256a), −h₃×w_(256a)),    (h₆×w_(256a), −h₂×w_(256a)), (h₆×w_(256a), −h₁×w_(256a)),-   (h₅×w_(256a), 15×w_(256a)), (h₅×w_(256a), h₇×w_(256a)),    (h₅×w_(256a), h₆×w_(256a)), (h₅×w_(256a), h₅×w_(256a)),    (h₅×w_(256a), h₄×w_(256a)), (h₅×w_(256a), h₃×w_(256a)),    (h₅×w_(256a), h₂×w_(256a)), (h₅×w_(256a), h₁×w_(256a)),    (h₅×w_(256a), −15×w_(256a)), (h₅×w_(256a), −h₇×w_(256a)),    (h₅×w_(256a), −h₆×w_(256a)), (h₅×w_(256a), −h₅×w_(256a)),    (h₅×w_(256a), −h₄×w_(256a)), (h₅×w_(256a), −h₃×w_(256a)),    (h₅×w_(256a), −h₂×w_(256a)), (h₅×w_(256a), −h₁×w_(256a)),-   (h₄×w_(256a), 15×w_(256a)), (h₄×w_(256a), h₇×w_(256a)),    (h₄×w_(256a), h₆×w_(256a)), (h₄×w_(256a), h₅×w_(256a)),    (h₄×w_(256a), h₄×w_(256a)), (h₄×w_(256a), h₃×w_(256a)),    (h₄×w_(256a), h₂×w_(256a)), (h₄×w_(256a), h₁×w_(256a)),    (h₄×w_(256a), −15×w_(256a)), (h₄×w_(256a), −h₇×w_(256a)),    (h₄×w_(256a), −h₆×w_(256a)), (h₄×w_(256a), −h₅×w_(256a)),    (h₄×w_(256a), −h₄×w_(256a)), (h₄×w_(256a), −h₃×w_(256a)),    (h₄×w_(256a), −h₂×w_(256a)), (h₄×w_(256a), −h₁×w_(256a)),-   (h₃×w_(256a), 15×w_(256a)), (h₃×w_(256a), h₇×w_(256a)),    (h₃×w_(256a), h₆×w_(256a)), (h₃×w_(256a), h₅×w_(256a)),    (h₃×w_(256a), h₄×w_(256a)), (h₃×w_(256a), h₃×w_(256a)),    (h₃×w_(256a), h₂×w_(256a)), (h₃×w_(256a), h₁×w_(256a)),    (h₃×w_(256a), −15×w_(256a)), (h₃×w_(256a), −h₇×w_(256a)),    (h₃×w_(256a), −h₆×w_(256a)), (h₃×w_(256a), −h₅×w_(256a)),    (h₃×w_(256a), −h₄×w_(256a)), (h₃×w_(256a), −h₃×w_(256a)),    (h₃×w_(256a), −h₂×w_(256a)), (h₃×w_(256a), −h₁×w_(256a)),-   (h₂×w_(256a), 15×w_(256a)), (h₂×w_(256a), h₇×w_(256a)),    (h₂×w_(256a), h₆×w_(256a)), (h₂×w_(256a), h₅×w_(256a)),    (h₂×w_(256a), h₄×w_(256a)), (h₂×w_(256a), h₃×w_(256a)),    (h₂×w_(256a), h₂×w_(256a)), (h₂×w_(256a), h₁×w_(256a)),    (h₂×w_(256a), −15×w_(256a)), (h₂×w_(256a), −h₇×w_(256a)),    (h₂×w_(256a), −h₆×w_(256a)), (h₂×w_(256a), −h₅×w_(256a)),    (h₂×w_(256a), −h₄×w₂₅₆), (h₂×w_(256a), −h₃×w_(256a)), (h₂×w_(256a),    −h₂×w_(256a)), (h₂×w_(256a), −h₁×w_(256a)),-   (h₁×w_(256a), 15×w_(256a)), (h₁×w_(256a), h₇×w_(256a)),    (h₁×w_(256a), h₆×w_(256a)), (h₁×w_(256a), h₅×w_(256a)),    (h₁×w_(256a), h₄×w_(256a)), (h₁×w_(256a), h₃×w_(256a)),    (h₁×w_(256a), h₂×w_(256a)), (h₁×w_(256a), h₁×w_(256a)),    (h₁×w_(256a), −15×w_(256a)), (h₁×w_(256a), −h₇×w_(256a)),    (h₁×w_(256a), −h₆×w_(256a)), (h₁×w_(256a), −h₅×w_(256a)),    (h₁×w_(256a), −h₄×w_(256a)), (h₁×w_(256a), −h₃×w_(256a)),    (h₁×w_(256a), −h₂×w_(256a)), (h₁×w_(256a), −h₁×w_(256a)),-   (−15×w_(256a), 15×w_(256a), (−15×w_(256a), h₇×w_(256a)),    (−15×w_(256a), h₆×w_(256a)), (−15×w_(256a), h₅×w_(256a)),    (−15×w_(256a), h₄×w_(256a)), (−15×w_(256a), h₃×w_(256a)),    (−15×w_(256a), h₂×w_(256a)), (−15×w_(256a), h₁×w_(256a)),    (−15×w_(256a), −15×w_(256a)), (−15×w_(256a), −h₇×w_(256a)),    (−15×w_(256a), −h₆×w_(256a)), (−15×w_(256a), −h₅×w_(256a)),    (−15×w_(256a), −h₄×w_(256a)), (−15×w_(256a), −h₃×w_(256a)),    (−15×w_(256a), −h₂×w_(256a)), (−15×w_(256a), −h₁×w_(256a)),-   (−h₇×w_(256a), 15×w_(256a)), (−h₇×w_(256a), h₇×w_(256a)),    (−h₇×w_(256a), h₆×w_(256a)), (−h₇×w_(256a), h₅×w_(256a)),    (−h₇×w_(256a), h₄×w_(256a)), (−h₇×w_(256a), h₃×w_(256a)),    (−h₇×w_(256a), h₂×w_(256a)), (−h₇×w_(256a), h₁×w_(256a)),    (−h₇×w_(256a), −15×w_(256a)), (−h₇×w_(256a), −h₇×w_(256a)),    (−h₇×w_(256a), −h₆×w_(256a)), (−h₇×w_(256a), −h₅×w_(256a)),    (−h₇×w_(256a), −h₄×w_(256a)), (−h₇×w_(256a), −h₃×w_(256a)),    (−h₇×w_(256a), −h₂×w_(256a)), (−h₇×w_(256a), −h₁×w_(256a)),-   (−h₆×w_(256a), 15×w_(256a)), (−h₆×w_(256a), h₇×w_(256a)),    (−h₆×w_(256a), h₆×w_(256a)), (−h₆×w_(256a), h₅×w_(256a)),    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h₄×w_(256a)), (−h₂×w_(256a), h₃×w_(256a)),    (−h₂×w_(256a), h₂×w_(256a)), (−h₂×w_(256a), h₁×w_(256a)),    (−h₂×w_(256a), −15×w_(256a)), (−h₂×w_(256a), −h₇×w_(256a)),    (−h₂×w_(256a), −h₆×w_(256a)), (−h₂×w_(256a), −h₅×w_(256a)),    (−h₂×w_(256a), −h₄×w_(256a)), (−h₂×w_(256a), −h₃×w_(256a)),    (−h₂×w_(256a), −h₂×w_(256a)), (−h₂×w_(256a), −h₁×w_(256a)),-   (−h₁×w_(256a), 15×w_(256a)), (−h₁×w_(256a), h₇×w_(256a)),    (−h₁×w_(256a), h₆×w_(256a)), (−h₁×w_(256a), h₅×w_(256a)),    (−h₁×w_(256a), h₄×w_(256a)), (−h₁×w_(256a), h₃×w_(256a)),    (−h₁×w_(256a), h₂×w_(256a)), (−h₁×w_(256a), h₁×w_(256a)),    (−h₁×w_(256a), −15×w_(256a)), (−h₁×w_(256a), −h₇×w_(256a)),    (−h₁×w_(256a), −h₆×w_(256a)), (−h₁×w_(256a), −h₅×w_(256a)),    (−h₁×w_(256a), −h₄×w_(256a)), (−h₁×w_(256a), −h₃×w_(256a)),    (−h₁×w_(256a), −h₂×w_(256a))₇ (−h₁×w_(256a), −h₁×w_(256a)), where    w_(256a) is a real number greater than 0.

In FIG. 9, the bits (input bits) to be transmitted are set to b0, b1,b2, b3, b4, b5, b6, and b7. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5,b6,b7)=(0,0,0,0,0,0,0,0) are mapped in signal pointH701 of FIG. 9 and (I,Q)=(15×w_(256a), 15×w_(256a)) is obtained, where Iand Q are the in-phase component and the orthogonal component of thepost-mapping baseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 256 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5,b6,b7). An example of therelationship between a set of b0, b1, b2, b3, b4, b5, b6, and b7(00000000 to 11111111) and the coordinates of the signal point isindicated in FIG. 9. The values of the sets of b0, b1, b2, b3, b4, b5,b6, and b7 (00000000 to 11111111) are indicated immediately below the256 signal points (the marks “◯” in FIG. 9) of 256 QAM:

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h₄×w_(256a)), (−h₆×w_(256a), h₃×w_(256a)),    (−h₆×w_(256a), h₂×w_(256a)), (−h₆×w_(256a), h₁×w_(256a)),    (−h₆×w_(256a), −15×w_(256a)), (−h₆×w_(256a), −h₇×w_(256a)),    (−h₆×w_(256a), −h₆×w_(256a)), (−h₆×w_(256a), −h₅×w_(256a)),    (−h₆×w_(256a), −h₄×w_(256a)), (−h₆×w_(256a), −h₃×w_(256a)),    (−h₆×w_(256a), −h₂×w_(256a)), (−h₆×w_(256a), −h₁×w_(256a)),-   (−h₅×w_(256a), 15×w_(256a)), (−h₅×w_(256a), h₇×w_(256a)),    (−h₅×w_(256a), h₆×w_(256a)), (−h₅×w_(256a), h₅×w_(256a)),    (−h₅×w_(256a), h₄×w_(256a)), (−h₅×w_(256a), h₃×w_(256a)),    (−h₅×w_(256a), h₂×w_(256a)), (−h₅×w_(256a), h₁×w_(256a)),    (−h₅×w_(256a), −15×w_(256a)), (−h₅×w_(256a), −h₇×w_(256a)),    (−h₅×w_(256a), −h₆×w_(256a)), (−h₅×w_(256a), −h₅×w_(256a)),    (−h₅×w_(256a), −h₄×w_(256a)), (−h₅×w_(256a), −h₃×w_(256a)),    (−h₅×w_(256a), −h₂×w_(256a)), (−h₅×w_(256a), −h₁×w_(256a)),-   (−h₄×w_(256a), 15×w_(256a)), (−h₄×w_(256a), h₇×w_(256a)),    (−h₄×w_(256a), h₆×w_(256a)), (−h₄×w_(256a), h₅×w_(256a)),    (−h₄×w_(256a), h₄×w_(256a)), (−h₄×w_(256a), h₃×w_(256a)),    (−h₄×w_(256a), h₂×w_(256a)), (−h₄×w_(256a), h₁×w_(256a)),    (−h₄×w_(256a), −15×w_(256a)), (−h₄×w_(256a), −h₇×w_(256a)),    (−h₄×w_(256a), −h₆×w_(256a)), (−h₄×w_(256a), −h₅×w_(256a)),    (−h₄×w_(256a), −h₄×w_(256a)), (−h₄×w_(256a), −h₃×w_(256a)),    (−h₄×w_(256a), −h₂×w_(256a))₇ (−h₄×w_(256a), −h₁×w_(256a)),-   (−h₃×w_(256a), 15×w_(256a)), (−h₃×w_(256a), h₇×w_(256a)),    (−h₃×w_(256a), h₆×w_(256a)), (−h₃×w_(256a), h₅×w_(256a)),    (−h₃×w_(256a), h₄×w_(256a)), (−h₃×w_(256a), h₃×w_(256a)),    (−h₃×w_(256a), h₂×w_(256a)), (−h₃×w_(256a), h₁×w_(256a)),    (−h₃×w_(256a), −15×w_(256a)), (−h₃×w_(256a), −h₇×w_(256a)),    (−h₃×w_(256a), −h₆×w_(256a)), (−h₃×w_(256a), −h₅×w_(256a)),    (−h₃×w_(256a), −h₄×w_(256a)), (−h₃×w_(256a), −h₃×w_(256a)),    (−h₃×w_(256a), −h₂×w_(256a)), (−h₃×w_(256a), −h₁×w_(256a)),-   (−h₂×w_(256a), 15×w_(256a)), (−h₂×w_(256a), h₇×w_(256a)),    (−h₂×w_(256a), h₆×w_(256a)), (−h₂×w_(256a), h₅×w_(256a)),    (−h₂×w_(256a), h₄×w_(256a)), (−h₂×w_(256a), h₃×w_(256a)),    (−h₂×w_(256a), h₂×w_(256a)), (−h₂×w_(256a), h₁×w_(256a)),    (−h₂×w_(256a), −15×w_(256a)), (−h₂×w_(256a), −h₇×w_(256a)),    (−h₂×w_(256a), −h₆×w_(256a)), (−h₂×w_(256a), −h₅×w_(256a)),    (−h₂×w_(256a), −h₄×w_(256a)), (−h₂×w_(256a), −h₃×w_(256a)),    (−h₂×w_(256a), −h₂×w_(256a)), (−h₂×w_(256a), −h₁×w_(256a)),-   (−h₁×w_(256a), 15×w_(256a)), (−h₁×w_(256a), h₇×w_(256a)),    (−h₁×w_(256a), h₆×w_(256a)), (−h₁×w_(256a), h₅×w_(256a)),    (−h₁×w_(256a), h₄×w_(256a)), (−h₁×w_(256a), h₃×w_(256a)),    (−h₁×w_(256a), h₂×w_(256a)), (−h₁×w_(256a), h₁×w_(256a)),    (−h₁×w_(256a), −15×w_(256a)), (−h₁×w_(256a), −h₇×w_(256a)),    (−h₁×w_(256a), −h₆×w_(256a)), (−h₁×w_(256a), −h₅×w_(256a)),    (−h₁×w_(256a), −h₄×w_(256a)), (−h₁×w_(256a), −h₃×w_(256a)),    (−h₁×w_(256a), −h₂×w_(256a)), (−h₁×w_(256a), −h₁×w_(256a)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, b3, b4, b5, b6,    and b7 (00000000 to 11111111) serve as in-phase component I and    orthogonal component Q of the post-mapping baseband signal. The    relationship between the set of b0, b1, b2, b3, b4, b5, b6, and b7    (00000000 to 11111111) in 256 QAM and the coordinates of the signal    point is not limited to that illustrated in FIG. 9.

The 256 signal points in FIG. 9 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 255”, and “signal point 256”(because 256 signal points exist, “signal point 1” to “signal point 256”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(256a) is given as follows.

[Mathematical  formula  7] $\begin{matrix}{w_{256a} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{256}\; D_{i}^{2}}{256}}}} & ( {{Equation}\mspace{14mu} 7} )\end{matrix}$

From (Equation 7), an average power of the post-mapping baseband signalis z².

The 256 QAM mapping method is generally called non-uniform 256 QAM.However, in this case, the 256 QAM mapping method is referred to as “256QAM mapping method #1”.

The mapping method in the case of“(h_(a1),h_(a2),h_(a3),h_(a4),h_(a5),h_(a6),h_(a7))=(1,3,5,7,9,11,13)”in the above description is referred to as uniform 256 QAM, and ishereinafter referred to as “256 QAM mapping method #0”.

FIG. 10 illustrates an example of the 256 QAM signal point arrangementin the in-phase I-orthogonal Q plane. In FIG. 10, 256 marks “◯” (whitecircle) indicate the 256 QAM signal points, the horizontal axisindicates the in-phase component I, and the vertical axis indicates theorthogonal component Q.

In FIG. 10, h₁>0 (h₁ is a real number greater than 0) and h₂>0 (h₂ is areal number greater than 0) and h₃>0 (h₃ is a real number greater than0) and h₄>0 (h₄is a real number greater than 0) and h₅>0 (h₅ is a realnumber greater than 0) and h₆>0 (h₆ is a real number greater than 0) andh₇>0 (h₇ is a real number greater than 0) and h₈>0 (h₈ is a real numbergreater than 0) and h₉>0 (h₉ is a real number greater than 0) and h₁₀>0(h₁₀ is a real number greater than 0) and h₁₁>0 (h₁₁ is a real numbergreater than 0) and h₁₂>0 (h₁₂ is a real number greater than 0) andh₁₃>0 (h₁₃ is a real number greater than 0) and h₁₄>0 (h₁₄ is a realnumber greater than 0) hold, and

-   {h₁≠15 and h₂≠15 and h₃≠15 and h₄≠15 and h₅≠15 and h₆≠15 and h₇≠15-   and h₁≠h₂ and h₁≠h₃ and h₁≠h₄ and h₁≠h₅ and h₁≠h₆ and h₁≠h₇-   and h₂≠h₃ and h₂≠h₄ and h₂≠h₅ and h₂≠h₆ and h₂≠h₇-   and h₃≠h₄ and h₃≠h₅ and h₃≠h₆ and h₃≠h₇-   and h₄≠h₅ and h₄≠h₆ and h₄≠h₇-   and h₅≠h₆ and h₅≠h₇-   and h₆≠h₇}-   and-   {h₈≠15 and h₉≠15 and h₁₀≠15 and h₁₁≠15 and h₁₂≠15 and h₁₃≠15 and    h₁₄≠15-   and h₈≠h₉ and h₈≠h₁₀ and h₈≠h₁₁ and h₈≠h₁₂ and h₈≠h₁₃ and h₈≠h₁₄-   and h₉≠h₁₀ and h₉≠h₁₁ and h₉≠h₁₂ and h₉≠h₁₃ and h₉≠h₁₄-   and h₁₀≠h₁₁ and h₁₀≠h₁₂ and h₁₀≠h₁₃ and h₁₀≠h₁₄-   and h₁₁≠h₁₂ and h₁₁≠h₁₃ and h₁₁≠h₁₄-   and h₁₂≠h₁₃ and h₁₂≠h₁₄-   and h₁₃≠h₁₄}-   and-   {h₁≠h₈ or h₂≠h₉ or h₃≠h₁₀ or h₄≠h₁₁ or h₅≠h₁₂ or h₆≠h₁₃ or h₇≠h₁₄    holds} hold.

In the in-phase I-orthogonal Q plane, coordinates of the 256 signalpoints (in FIG. 10, the mark “◯” indicates the signal point) for 256 QAMare expressed as follows:

-   (15×w_(256b), 15×w_(256b)), (15×w_(256b), h₁₄×w_(256b)),    (15×w_(256b), h₁₃×w_(256b)), (15×w_(256b), h₁₂×w_(256b)),    (15×w_(256b), h₁₁×w_(256b)), (15×w_(256b), h₁₀×w_(256b)),    (15×w_(256b), h₉×w_(256b)), (15×w_(256b), h₈×w_(256b)),    (15×w_(256b), −15×w_(256b)), (15×w_(256b), −h₁₄×w_(256b)),    (15×w_(256b), −h₁₃×w_(256b)), (15×w_(256b), −h₁₂×w_(256b)),    (15×w_(256b), −h₁₁×w_(256b)), (15×w_(256b), −h₁₀×w_(256b)),    (15×w_(256b), −h₉×w_(256b)), (15×w_(256b), −h₈×w_(256b)),-   (h₇×w_(256b), 15×w_(256b)), (h₇×w_(256b), h₁₄×w_(256b)),    (h₇×w_(256b), h₁₃×w_(256b)), (h₇×w_(256b), h₁₂×w_(256b)),    (h₇×w_(256b), h₁₁×w_(256b)), (h₇×w_(256b), h₁₀×w_(256b)),    (h₇×w_(256b), h₉×w_(256b)), (h₇×w_(256b), h₈×w_(256b)),    (h₇×w_(256b), −15×w_(256b)), (h₇×w_(256b), −h₁₄×w_(256b)),    (h₇×w_(256b), −h₁₃×w_(256b)), (h₇×w_(256b), −h₁₂×w_(256b)),    (h₇×w_(256b), −h₁₁×w_(256b)), (h₇×w_(256b), −h₁₀×w_(256b)),    (h₇×w_(256b), −h₉×w_(256b)), (h₇×w_(256b), −h₈×w_(256b)),-   (h₆×w_(256b), 15×w_(256b)), (h₆×w_(256b), h₁₄×w_(256b)),    (h₆×w_(256b), h₁₃×w_(256b)), (h₆×w_(256b), h₁₂×w_(256b)),    (h₆×w_(256b), h₁₁×w_(256b)), (h₆×w_(256b), h₁₀×w_(256b)),    (h₆×w_(256b), h₉×w_(256b)), (h₆×w_(256b), h₈×w_(256b)),    (h₆×w_(256b), −15×w_(256b)), (h₆×w_(256b), −h₁₄×w_(256b)),    (h₆×w_(256b), −h₁₃×w_(256b)), (h₆×w_(256b), −h₁₂×w_(256b)),    (h₆×w_(256b), −h₁₁×w_(256b)), (h₆×w_(256b), −h₁₀×w_(256b)),    (h₆×w_(256b), −h₉×w_(256b)), (h₆×w_(256b), −h₈×w_(256b)),-   (h₅×w_(256b), 15×w_(256b)), (h₅×w_(256b), h₁₄×w_(256b)),    (h₅×w_(256b), h₁₃×w_(256b)), (h₅×w_(256b), h₁₂×w_(256b)),    (h₅×w_(256b), h₁₁×w_(256b)), (h₅×w_(256b), h₁₀×w_(256b)),    (h₅×w_(256b), h₉×w_(256b)), (h₅×w_(256b), h₈×w_(256b)),    (h₅×w_(256b), −15×w_(256b)), (h₅×w_(256b), −h₁₄×w_(256b)),    (h₅×w_(256b), −h₁₃×w_(256b)), (h₅×w_(256b), −h₁₂×w_(256b)),    (h₅×w_(256b), −h₁₁×w_(256b)), (h₅×w_(256b), −h₁₀×w_(256b)),    (h₅×w_(256b), −h₉×w_(256b)), (h₅×w_(256b), −h₈×w_(256b)),-   (h₄×w_(256b), 15×w_(256b)), (h₄×w_(256b), h₁₄×w_(256b)),    (h₄×w_(256b), h₁₃×w_(256b)), (h₄×w_(256b), h₁₂×w_(256b)),    (h₄×w_(256b), h₁₁×w_(256b)), (h₄×w_(256b), h₁₀×w_(256b)),    (h₄×w_(256b), h₉×w_(256b)), (h₄×w_(256b), h₈×w_(256b)),    (h₄×w_(256b), −15×w_(256b)), (h₄×w_(256b), −h₁₄×w_(256b)),    (h₄×w_(256b), −h₁₃×w_(256b)), (h₄×w_(256b), −h₁₂×w_(256b)),    h₄×w_(256b), −h₁₁×w_(256b)), (h₄×w_(256b), −h₁₀×w_(256b)),    (h₄×w_(256b), −h₉×w_(256b)), (h₄×w_(256b), −h₈×w_(256b)),-   (h₃×w_(256b), 15×w_(256b)), (h₃×w_(256b), h₁₄×w_(256b)),    (h₃×w_(256b), h₁₃×w_(256b)), (h₃×w_(256b), h₁₂×w_(256b)),    (h₃×w_(256b), h₁₁×w_(256b)), (h₃×w_(256b), h₁₀×w_(256b)),    (h₃×w_(256b), h₉×w_(256b)), (h₃×w_(256b), h₈×w_(256b)),    (h₃×w_(256b), −15×w_(256b)), (h₃×w_(256b), −h₁₄×w_(256b)),    (h₃×w_(256b), −h₁₃×w_(256b)), (h₃×w_(256b), −h₁₂×w_(256b)),    h₃×w_(256b), −h₁₁×w_(256b)), (h₃×w_(256b), −h₁₀×w_(256b)),    (h₃×w_(256b), −h₉×w_(256b)), (h₃×w_(256b), −h₈×w_(256b)),-   (h₂×w_(256b), 15×w_(256b)), (h₂×w_(256b), h₁₄×w_(256b)),    (h₂×w_(256b), h₁₃×w_(256b)), (h₂×w_(256b), h₁₂×w_(256b)),    (h₂×w_(256b), h₁₁×w_(256b)), (h₂×w_(256b), h₁₀×w_(256b)),    (h₂×w_(256b), h₉×w_(256b)), (h₂×w_(256b), h₈×w_(256b)),    (h₂×w_(256b), −15×w_(256b)), (h₂×w_(256b), −h₁₄×w_(256b)),    (h₂×w_(256b), −h₁₃×w_(256b)), (h₂×w_(256b), −h₁₂×w_(256b)),    (h₂×w_(256b), −h₁₁×w_(256b)), (h₂×w_(256b), −h₁₀×w_(256b)),    (h₂×w_(256b), −h₉×w_(256b)), (h₂×w_(256b), −h₈×w_(256b)),-   (h₁×w_(256b), 15×w_(256b)), h₁×w_(256b), h₁₄×w_(256b)),    (h₁×w_(256b), h₁₃×w_(256b)), (h₁×w_(256b), h₁₂×w_(256b)),    (h₁×w_(256b), h₁₁×w_(256b)), (h₁×w_(256b), h₁₀×w_(256b)),    (h₁×w_(256b), h₉×w_(256b)), (h₁×w_(256b), h₈×w_(256b)),    (h₁×w_(256b), −15×w_(256b)), (h₁×w_(256b), −h₁₄×w_(256b)),    (h₁×w_(256b), −h₁₃×w_(256b)), (h₁×w_(256b), −h₁₂×w_(256b)),    (h₁×w_(256b), −h₁₁×w_(256b)), (h₁×w_(256b), −h₁₀×w_(256b)),    (h₁×w_(256b), −h₉×w_(256b)), (h₁×w_(256b), −h₈×w_(256b)),-   (−15×w_(256b), 15×w_(256b)), (−15×w_(256b), h₁₄×w_(256b)),    (−15×w_(256b), h₁₃×w_(256b)), (−15×w_(256b), h₁₂×w_(256b)),    (−15×w_(256b), h₁₁×w_(256b)), (−15×w_(256b), h₁₀×w_(256b)),    (−15×w_(256b), h₉×w_(256b)), (−15×w_(256b), h₈×w_(256b)),    (−15×w_(256b), −15×w_(256b)), (−15×w_(256b), −h₁₄×w_(256b)),    (−15×w_(256b), −h₁₃×w_(256b)), (−15×w_(256b), −h₁₂×w_(256b)),    (−15×w_(256b), −h₁₁×w_(256b)), (−15×w_(256b), −h₁₀×w_(256b)),    (−15×w_(256b), −h₉×w_(256b)), (−15×w_(256b), −h₈×w_(256b)),-   (−h₇×w_(256b), 15×w_(256b)), (−h₇×w_(256b), h₁₄×w_(256b)),    (−h₇×w_(256b), h₁₃×w_(256b)), (−h₇×w_(256b), h₁₂×w_(256b)),    (−h₇×w_(256b), h₁₁×w_(256b)), (−h₇×w_(256b), h₁₀×w_(256b)),    (−h₇×w_(256b), h₉×w_(256b)), (−h₇×w_(256b), h₈×w_(256b)),    (−h₇×w_(256b), −15×w_(256b)), (−h₇×w_(256b), −h₁₄×w_(256b)),    (−h₇×w_(256b), −h₁₃×w_(256b)), (−h₇×w_(256b), −h₁₂×w_(256b)),    (−h₇×w_(256b), −h₁₁×w_(256b)), (−h₇×w_(256b), −h₁₀×w_(256b)),    (−h₇×w_(256b), −h₉×w_(256b)), (−h₇×w_(256b), −h₈×w_(256b)),-   (−h₆×w_(256b), 15×w_(256b)), (−h₆×w_(256b), h₁₄×w_(256b)),    (−h₆×w_(256b), h₁₃×w_(256b)), (−h₆×w_(256b), h₁₂×w_(256b)),    (−h₆×w_(256b), h₁₁×w_(256b)), (−h₆×w_(256b), h₁₀×w_(256b)),    (−h₆×w_(256b), h₉×w_(256b)), (−h₆×w_(256b), h₈×w_(256b)),    (−h₆×w_(256b), −15×w_(256b)), (−h₆×w_(256b), −h₁₄×w_(256b)),    (−h₆×w_(256b), −h₁₃×w_(256b)), (−h₆×w_(256b), −h₁₂×w_(256b)),    (−h₆×w_(256b), −h₁₁×w_(256b)), (−h₆×w_(256b), −h₁₀×w_(256b)),    (−h₆×w_(256b), −h₉×w_(256b)), (−h₆×w_(256b), −h₈×w_(256b)),-   (−h₅×w_(256b), 15×w_(256b)), (−h₅×w_(256b), h₁₄×w_(256b)),    (−h₅×w_(256b), h₁₃×w_(256b)), (−h₅×w_(256b), h₁₂×w_(256b)),    (−h₅×w_(256b), h₁₁×w_(256b)), (−h₅×w_(256b), h₁₀×w_(256b)),    (−h₅×w_(256b), h₉×w_(256b)), (−h₅×w_(256b), h₈×w_(256b)),    (−h₅×w_(256b), −15×w_(256b)), (−h₅×w_(256b), −h₁₄×w_(256b)),    (−h₅×w_(256b), −h₁₃×w_(256b)), (−h₅×w_(256b), −h₁₂×w_(256b)),    (−h₅×w_(256b), −h₁₁×w_(256b)), (−h₅×w_(256b), −h₁₀×w_(256b)),    (−h₅×w_(256b), −h₉×w_(256b)), (−h₅×w_(256b), −h₈×w_(256b)),-   (−h₄×w_(256b), 15×w_(256b)), (−h₄×w_(256b), h₁₄×w_(256b)),    (−h₄×w_(256b), h₁₃×w_(256b)), (−h₄×w_(256b), h₁₂×w_(256b)),    (−h₄×w_(256b), h₁₁×w_(256b)), (−h₄×w_(256b), h₁₀×w_(256b)),    (−h₄×w_(256b), h₉×w_(256b)), (−h₄×w_(256b), h₈×w_(256b)),    (−h₄×w_(256b), −15×w_(256b)), (−h₄×w_(256b), −h₁₄×w_(256b)),    (−h₄×w_(256b), −h₁₃×w_(256b)), (−h₄×w_(256b), −h₁₂×w_(256b)),    (−h₄×w_(256b), −h₁₁×w_(256b)), (−h₄×w_(256b), −h₁₀×w_(256b)),    (−h₄×w_(256b), −h₉×w_(256b)), (−h₄×w_(256b), −h₈×w_(256b)),-   (−h₃×w_(256b), 15×w_(256b)), (−h₃×w_(256b), h₁₄×w_(256b)),    (−h₃×w_(256b), h₁₃×w_(256b)), (−h₃×w_(256b), h₁₂×w_(256b)),    (−h₃×w_(256b), h₁₁×w_(256b)), (−h₃×w_(256b), h₁₀×w_(256b)),    (−h₃×w_(256b), h₉×w_(256b)), (−h₃×w_(256b), h₈×w_(256b)),    (−h₃×w_(256b), −15×w_(256b)), (−h₃×w_(256b), −h₁₄×w_(256b)),    (−h₃×w_(256b), −h₁₃×w_(256b)), (−h₃×w_(256b), −h₁₂×w_(256b)),    (−h₃×w_(256b), −h₁₁×w_(256b)), (−h₃×w_(256b), −h₁₀×w_(256b)),    (−h₃×w_(256b), −h₉×w_(256b)), (−h₃×w_(256b), −h₈×w_(256b)),-   (−h₂×w_(256b), 15×w_(256b)), (−h₂×w_(256b), h₁₄×w_(256b)),    (−h₂×w_(256b), h₁₃×w_(256b)), (−h₂×w_(256b), h₁₂×w_(256b)),    (−h₂×w_(256b), h₁₁×w_(256b)), (−h₂×w_(256b), h₁₀×w_(256b)),    (−h₂×w_(256b), h₉×w_(256b)), (−h₂×w_(256b), h₈×w_(256b)),    (−h₂×w_(256b), −15×w_(256b)), (−h₂×w_(256b), −h₁₄×w_(256b)),    (−h₂×w_(256b), −h₁₃×w_(256b)), (−h₂×w_(256b), −h₁₂×w_(256b)),    (−h₂×w_(256b), −h₁₁×w_(256b)), (−h₂×w_(256b), −h₁₀×w_(256b)),    (−h₂×w_(256b), −h₉×w_(256b)), (−h₂×w_(256b), −h₈×w_(256b)),-   (−h₁×w_(256b), 15×w_(256b)), (−h₁×w_(256b), h₁₄×w_(256b)),    (−h₁×w_(256b), h₁₃×w_(256b)), (−h₁×w_(256b), h₁₂×w_(256b)),    (−h₁×w_(256b), h₁₁×w_(256b)), (−h₁×w_(256b), h₁₀×w_(256b)),    (−h₁×w_(256b), h₉×w_(256b)), (−h₁×w_(256b), h₈×w_(256b)),    (−h₁×w_(256b), −15×w_(256b)), (−h₁×w_(256b), −h₁₄×w_(256b)),    (−h₁×w_(256b), −h₁₃×w_(256b)), (−h₁×w_(256b), −h₁₂×w_(256b)),    (−h₁×w_(256b), −h₁₁×w_(256b)), (−h₁×w_(256b), −h₁₀×w_(256b)),    (−h₁×w_(256b), −h₉×w_(256b)), (−h₁×w_(256b), −h₈×w_(256b)), where    w_(256b) is a real number greater than 0.

In FIG. 10, the bits (input bits) to be transmitted are set to b0, b1b2, b3, b4, b5, b6, and b7. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5,b6,b7)=(0,0,0,0,0,0,0,0) are mapped in signal pointH801 of FIG. 10 and (I,Q)=(15×w_(256b), 15×w_(256b)) is obtained, whereI and Q are the in-phase component and the orthogonal component of thepost-mapping baseband signal, respectively.

That is, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 256 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5,b6,b7). An example of therelationship between a set of b0, b1 b2, b3, b4, b5, b6, and b7(00000000 to 11111111) and the coordinates of the signal point isindicated in FIG. 10. FIG. 10 illustrates the values of the sets of b0,b1 b2, b3, b4, b5, b6, and b7 (00000000 to 11111111) immediately belowthe 256 signal points (the marks “◯” in FIG. 10) of 256 QAM:

-   (15×w_(256b), 15×w_(256b)), (15×w_(256b), h₁₄×w_(256b)),    (15×w_(256b), h₁₃×w_(256b)), (15×w_(256b), h₁₂×w_(256b)),    (15×w_(256b), h₁₁×w_(256b)), (15×w_(256b), h₁₀×w_(256b)),    (15×w_(256b), h₉×w_(256b)), (15×w_(256b), h₈×w_(256b)),    (15×w_(256b), −15×w_(256b)), (15×w_(256b), −h₁₄×w_(256b)),    (15×w_(256b), −h₁₃×w_(256b)), (15×w_(255b), −h₁₂×w_(256b)),    (15×w_(256b), −h₁₁×w_(256b)), (15×w_(256b), −h₁₀×w_(256b)),    (15×w_(256b), −h₉×w_(256b)), (15×w_(256b), −h₈×w_(256b)),-   (h₇×w_(256b), 15×w_(256b)), (h₇×w_(256b), h₁₄×w_(256b)),    (h₇×w_(256b), h₁₃×w_(256b)), (h₇×w_(256b), h₁₂×w_(256b)),    (h₇×w_(256b), h₁₁×w_(256b)), (h₇×w_(256b), h₁₀×w_(256b)),    (h₇×w_(256b), h₉×w_(256b)), (h₇×w_(256b), h₈×w_(256b)),    (h₇×w_(256b), −15×w_(256b)), (h₇×w_(256b), −h₁₄×w_(256b)),    (h₇×w_(256b), −h₁₃×w_(256b)), (h₇×w_(256b), −h₁₂×w_(256b)),    (h₇×w_(256b), −h₁₁×w_(256b)), (h₇×w_(256b), −h₁₀×w_(256b)),    (h₇×w_(256b), −h₉×w_(256b)), (h₇×w_(256b), −h₈×w_(256b)),-   (h₆×w_(256b), 15×w_(256b)), (h₆×w_(256b), h₁₄×w_(256b)),    (h₆×w_(256b), h₁₃×w_(256b)), (h₆×w_(256b), h₁₂×w_(256b)),    (h₆×w_(256b), h₁₁×w_(256b)), (h₆×w_(256b), h₁₀×w_(256b)),    (h₆×w_(256b), h₉×w_(256b)), (h₆×w_(256b), h₈×w_(256b)),    (h₆×w_(256b), −15×w_(256b)), (h₆×w_(256b), −h₁₄×w_(256b)),    (h₆×w_(256b), −h₁₃×w_(256b)), (h₆×w_(256b), −h₁₂×w_(256b)),    (h₆×w_(256b), −h₁₁×w_(256b)), (h₆×w_(256b), −h₁₀×w_(256b)),    (h₆×w_(256b), −h₉×w_(256b)), (h₆×w_(256b), −h₆×w_(256b)),-   (h₅×w_(256b), 15×w_(256b)), (h₅×w_(256b), h₁₄×w_(256b)),    (h₅×w_(256b), h₁₃×w_(256b)), (h₅×w_(256b), h₁₂×w_(256b)),    (h₅×w_(256b), h₁₁×w_(256b)), (h₅×w_(256b), h₁₀×w_(256b)),    (h₅×w_(256b), h₉×w_(256b)), (h₅×w_(256b), h₈×w_(256b)),    (h₅×w_(256b), −15×w_(256b)), (h₅×w_(256b), −h₁₄×w_(256b)),    (h₅×w_(256b), −h₁₃×w_(256b)), (h₅×w_(256b), −h₁₂×w_(256b)),    (h₅×w_(256b), −h₁₁×w_(256b)), (h₅×w_(256b), −h₁₀×w_(256b)),    (h₅×w_(256b), −h₉×w_(256b)), (h₅×w_(256b), −h₈×w_(256b)),-   (h₄×w_(256b), 15×w_(256b)), (h₄×w_(256b), h₁₄×w_(256b)),    (h₄×w_(256b), h₁₃×w_(256b)), (h₄×w_(256b), h₁₂×w_(256b)),    (h₄×w_(256b), h₁₁×w_(256b)), (h₄×w_(256b), h₁₀×w_(256b)),    (h₄×w_(256b), h₉×w_(256b)), (h₄×w_(256b), h₈×w_(256b)),    (h₄×w_(256b), −15×w_(256b)), (h₄×w_(256b), −h₁₄×w_(256b)),    (h₄×w_(256b), −h₁₃×w_(256b)), (h₄×w_(256b), −h₁₂×w_(256b)),    (h₄×w_(256b), −h₁₁×w_(256b)), (h₄×w_(256b), −h₁₀×w_(256b)),    (h₄×w_(256b), −h₉×w_(256b)), (h₄×w_(256b), −h₈×w_(256b)),-   (h₃×w_(256b), 15×w_(256b)), (h₃×w_(256b), h₁₄×w_(256b)),    (h₃×w_(256b), h₁₃×w_(256b)), (h₃×w_(256b), h₁₂×w_(256b)),    (h₃×w_(256b), h₁₁×w_(256b)), (h₃×w_(256b), h₁₀×w_(256b)),    (h₃×w_(256b), h₉×w_(256b)), (h₃×w_(256b), h₈×w_(256b)),    (h₃×w_(256b), −15×w_(256b)), (h₃×w_(256b), −h₁₄×w_(256b)),    (h₃×w_(256b), −h₁₃×w_(256b)), (h₃×w_(256b), −h₁₂×w_(256b)),    (h₃×w_(256b), −h₁₁×w_(256b)), (h₃×w_(256b), −h₁₀×w_(256b)),    (h₃×w_(256b), −h₉×w_(256b)), (h₃×w_(256b), −h₈×w_(256b)),-   (h₂×w_(256b), 15×w_(256b)), (h₂×w_(256b), h₁₄×w_(256b)),    (h₂×w_(256b), h₁₃×w_(256b)), (h₂×w_(256b), h₁₂×w_(256b)),    (h₂×w_(256b), h₁₁×w_(256b)), (h₂×w_(256b), h₁₀×w_(256b)),    (h₂×w_(256b), h₉×w_(256b)), (h₂×w_(256b), h₈×w_(256b)),    (h₂×w_(256b), −15×w_(256b)), (h₂×w_(256b), −h₁₄×w_(256b)),    (h₂×w_(256b), −h₁₃×w_(256b)), (h₂×w_(256b), −h₁₂×w_(256b)),    (h₂×w_(256b), −h₁₁×w_(256b)), (h₂×w_(256b), −h₁₀×w_(256b)),    (h₂×w_(256b), −h₉×w_(256b)), (h₂×w_(256b), −h₈×w_(256b)),-   (h₁×w_(256b), 15×w_(256b)), (h₁×w_(256b), h₁₄×w_(256b)),    (h₁×w_(256b), h₁₃×w_(256b)), (h₁×w_(256b), h₁₂×w_(256b)),    (h₁×w_(256b), h₁₁×w_(256b)), (h₁×w_(256b), h₁₀×w_(256b)),    (h₁×w_(256b), h₉×w_(256b)), (h₁×w_(256b), h₈×w_(256b)),    (h₁×w_(256b), −15×w_(256b)), (h₁×w_(256b), −h₁₄×w_(256b)),    (h₁×w_(256b), −h₁₃×w_(256b)), (h₁×w_(256b), −h₁₂×w_(256b)),    h₁×w_(256b), −h₁₁×w_(256b)), (h₁×w_(256b), −h₁₀×w_(256b)),    (h₁×w_(256b), −h₉×w_(256b)), (h₁×w_(256b), −h₈×w_(256b)),-   (−15×w_(256b), 15×w_(256b)), (−15×w_(256b), h₁₄×w_(256b)),    (−15×w_(256b), h₁₃×w_(256b)), (−15×w_(256b), h₁₂×w_(256b)),    (−15×w_(256b), h₁₁×w_(256b)), (−15×w_(256b), h₁₀×w_(256b)),    (−15×w_(256b), h₉×w_(256b)), (−15×w_(256b), h₈×w_(256b)),    (−15×w_(256b), −15×w_(256b)), (−15×w_(256b), −h₁₄×w_(256b)),    (−15×w_(256b), −h₁₃×w_(256b)), (−15×w_(256b), −h₁₂×w_(256b)),    (−15×w_(256b), −h₁₁×w_(256b)) (−15×w_(256b), −h₁₀×w_(256b)),    (−15×w_(256b), −h₉×w_(256b)), (−15×w_(256b), −h₈×w_(256b)),-   (−h₇×w_(256b), 15×w_(256b)), (−h₇×w_(256b), h₁₄×w_(256b)),    (−h₇×w_(256b), h₁₃×w_(256b)), (−h₇×w_(256b), h₁₂×w_(256b)),    (−h₇×w_(256b), h₁₁×w_(256b)), (−h₇×w_(256b), h₁₀×w_(256b)),    (−h₇×w_(256b), h₉×w_(256b)), (−h₇×w_(256b), h₈×w_(256b)),    (−h₇×w_(256b), −15×w_(256b)), (−h₇×w_(256b), −h₁₄×w_(256b)),    (−h₇×w_(256b), −h₁₃×w_(256b)), (−h₇×w_(256b), −h₁₂×w_(256b)),    (−h₇×w_(256b), −h₁₁×w_(256b)), (−h₇×w_(256b), −h₁₀×w_(256b)),    (−h₇×w_(256b), −h₉×w_(256b)), (−h₇×w_(256b), −h₈×w_(256b)),-   (−h₆×w_(256b), 15×w_(256b)), (−h₆×w_(256b), h₁₄×w_(256b)),    (−h₆×w_(256b), h₁₃×w_(256b)), (−h₆×w_(256b), h₁₂×w_(256b)),    (−h₆×w_(256b), h₁₁×w_(256b)), (−h₆×w_(256b), h₁₀×w_(256b)),    (−h₆×w_(256b), h₉×w_(256b)), (−h₆×w_(256b), h₈×w_(256b)),    (−h₆×w_(256b), −15×w_(256b)), (−h₆×w_(256b), −h₁₄×w_(256b)),    (−h₆×w_(256b), −h₁₃×w_(256b)), (−h₆×w_(256b), −h₁₂×w_(256b)),    (−h₆×w_(256b), −h₁₁×w_(256b)), (−h₆×w_(256b), −h₁₀×w_(256b)),    (−h₆×w_(256b), −h₉×w_(256b)), (−h₆×w_(256b), −h₈×w_(256b)),-   (−h₅×w_(256b), 15×w_(256b)), (−h₅×w_(256b), h₁₄×w_(256b)),    (−h₅×w_(256b), h₁₃×w_(256b)), (−h₅×w_(256b), h₁₂×w_(256b)),    (−h₅×w_(256b), h₁₁×w_(256b)), (−h₅×w_(256b), h₁₀×w_(256b)),    (−h₅×w_(256b), h₉×w_(256b)), (−h₅×w_(256b), h₈×w_(256b)),    (−h₅×w_(256b), −15×w_(256b)), (−h₅×w_(256b), −h₁₄×w_(256b)),    (−h₅×w_(256b), −h₁₃×w_(256b)), (−h₅×w_(256b), −h₁₂×w_(256b)),    (−h₅×w_(256b), −h₁₁×w_(256b)), (−h₅×w_(256b), −h₁₀×w_(256b)),    (−h₅×w_(256b), −h₉×w_(256b)), (−h₅×w_(256b), −h₈×w_(256b)),-   (−h₄×w_(256b), 15×w_(256b)), (−h₄×w_(256b), h₁₄×w_(256b)),    (−h₄×w_(256b), h₁₃×w_(256b)), (−h₄×w_(256b), h₁₂×w_(256b)),    (−h₄×w_(256b), h₁₁×w_(256b)), (−h₄×w_(256b), h₁₀×w_(256b)),    (−h₄×w_(256b), h₉×w_(256b)), (−h₄×w_(256b), h₈×w_(256b)),    (−h₄×w_(256b), −15×w_(256b)), (−h₄×w_(256b), −h₁₄×w_(256b)),    (−h₄×w_(256b), −h₁₃×w_(256b)), (−h₄×w_(256b), −h₁₂×w_(256b)),    (−h₄×w_(256b), −h₁₁×w_(256b)), (−h₄×w_(256b), −h₁₀×w_(256b)),    (−h₄×w_(256b), −h₉×w_(256b)), (−h₄×w_(256b), −h₈×w_(256b)),-   (−h₃×w_(256b), 15×w_(256b)), (−h₃×w_(256b), h₁₄×w_(256b)),    (−h₃×w_(256b), h₁₃×w_(256b)), (−h₃×w_(256b), h₁₂×w_(256b)),    (−h₃×w_(256b), h₁₁×w_(256b)), (−h₃×w_(256b), h₁₀×w_(256b)),    (−h₃×w_(256b), h₉×w_(256b)), (−h₃×w_(256b), h₈×w_(256b)),    (−h₃×w_(256b), −15×w_(256b)), (−h₃×w_(256b), −h₁₄×w_(256b)),    (−h₃×w_(256b), −h₁₃×w_(256b)), (−h₃×w_(256b), −h₁₂×w_(256b)),    (−h₃×w_(256b), −h₁₁×w_(256b)), (−h₃×w_(256b), −h₁₀×w_(256b)),    (−h₃×w_(256b), −h₉×w_(256b)), (−h₃×w_(256b), −h₈×w_(256b)),-   (−h₂×w_(256b), 15×w_(256b)), (−h₂×w_(256b), h₁₄×w_(256b)),    (−h₂×w_(256b), h₁₃×w_(256b)), (−h₂×w_(256b), h₁₂×w_(256b)),    (−h₂×w_(256b), h₁₁×w_(256b)), (−h₂×w_(256b), h₁₀×w_(256b)),    (−h₂×w_(256b), h₉×w_(256b)), (−h₂×w_(256b), h₈×w_(256b)),    (−h₂×w_(256b), −15×w_(256b)), (−h₂×w_(256b), −h₁₄×w_(256b)),    (−h₂×w_(256b), −h₁₃×w_(256b)), (−h₂×w_(256b), −h₁₂×w_(256b)),    (−h₂×w_(256b), −h₁₁×w_(256b)), (−h₂×w_(256b), −h₁₀×w_(256b)),    (−h₂×w_(256b), −h₉×w_(256b)), (−h₂×w_(256b), −h₈×w_(256b)),-   (−h₁×w_(256b), 15×w_(256b)), (−h₁×w_(256b), h₁₄×w_(256b)),    (−h₁×w_(256b), h₁₃×w_(256b)), (−h₁×w_(256b), h₁₂×w_(256b)),    (−h₁×w_(256b), h₁₁×w_(256b)), (−h₁×w_(256b), h₁₀×w_(256b)),    (−h₁×w_(256b), h₉×w_(256b)), (−h₁×w_(256b), h₈×w_(256b)),    (−h₁×w_(256b), −15×w_(256b)), (−h₁×w_(256b), −h₁₄×w_(256b)),    (−h₁×w_(256b), −h₁₃×w_(256b)), (−h₁×w_(256b), −h₁₂×w_(256b)),    (−h₁×w_(256b), −h₁₁×w_(256b)), (−h₁×w_(256b), −h₁₀×w_(256b)),    (−h₁×w_(256b), −h₉×w_(256b)), (−h₁×w_(256b), −h₈×w_(256b)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, b3, b4, b5, b6,    and b7 (00000000 to 11111111) serve as in-phase component I and    orthogonal component Q of the post-mapping baseband signal. The    relationship between the set of b0, b1, b2, b3, b4, b5, b6, and b7    (00000000 to 11111111) in 256 QAM and the coordinates of the signal    point is not limited to that illustrated in FIG. 10.

The 256 signal points in FIG. 10 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 255”, and “signal point 256”(because 256 signal points exist, “signal point 1” to “signal point 256”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(256b) is given as follows.

[Mathematical  formula  8] $\begin{matrix}{w_{256b} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{256}\; D_{i}^{2}}{256}}}} & ( {{Equation}\mspace{14mu} 8} )\end{matrix}$

From (Equation 8), an average power of the post-mapping baseband signalis z².

Hereinafter, the 256 QAM mapping method is referred to as “256 QAMmapping method #2”.

FIG. 11 illustrates an example of the 256 QAM signal point arrangementin the in-phase I-orthogonal Q plane. In FIG. 11, 256 marks “◯” (whitecircle) indicate the 256 QAM signal points, the horizontal axisindicates the in-phase component I, and the vertical axis indicates theorthogonal component Q.

In FIG. 11,

-   “n₁>0 (n₁ is a real number greater than 0) and n₂>0 (n₂ is a real    number greater than 0) and n₃>0 (n₃ is a real number greater than 0)    and n₄>0 (n₄ is a real number greater than 0) and n₅>0 (n₅ is a real    number greater than 0) and n₆>0 (n₆ is a real number greater than 0)    and n₇>0 (n₇ is a real number greater than 0) and n₈>0 (n₈ is a real    number greater than 0) and n₉>0 (n₉ is a real number greater than 0)    and n₁₀>0 (n₁₀ is a real number greater than 0) and n₁₁>0 (n₁₁ is a    real number greater than 0) and n₁₂>0 (n₁₂ is a real number greater    than 0) and n₁₃>0 (n₁₃ is a real number greater than 0) and n₁₄>0    (n₁₄ is a real number greater than 0) and n₁₅>0 (n₁₅ is a real    number greater than 0) and n₁₆>0 (n₁₆ is a real number greater    than 0) hold, and-   {n₁≠n₂ and n₁≠n₃ and n₁≠n₄ and n₁≠n₅ and n₁≠n₆ and n₁≠n₇ and n₁≠n₈-   and n₂≠n₃ and n₂≠n₄ and n₂≠n₅ and n₂≠n₆ and n₂≠n₇ and n₂≠n₈-   and n₃≠n₄ and n₃≠n₅ and n 3≠n₆ and n₃≠n₇ and n₃≠n₈-   and n₄≠n₅ and n₄≠n₆ and n₄≠n₇ and n₄≠n₈-   and n₅≠n₆ and n₅≠n₇ and n₅≠n₈-   and n₆≠n₇ and n₆≠n₈-   and n₇≠n₈}-   and-   {n₉≠n₁₀ and n₉≠n₁₁ and n₉≠n₁₂ and n₉≠n₁₃ and n₉≠n₁₄ and n₉≠n₁₅ and    n₉≠n₁₆-   and n₁₀≠n₁₁ and n₁₀≠n₁₂ and n₁₀≠n₁₃ and n₁₀≠n₁₄ and n₁₀≠n₁₅ and    n₁₀≠n₁₆-   and n₁₁≠n₁₂ and n₁₁≠n₁₃ and n₁₁≠n₁₄ and n₁₁≠n₁₅ and n₁₁≠n₁₆-   and n₁₂≠n₁₃ and n₁₂≠n₁₄ and n₁₂≠n₁₅ and n₁₂≠n₁₆-   and n₁₃≠n₁₄ and n₁₃≠n₁₅ and n₁₃≠n₁₆-   and n₁₄≠n₁₅ and n₁₄≠n₁₆-   and n₁₅≠n₁₆}-   and-   {n₁≠n₉ or n₂≠n₁₀ or n₃≠n₁₁ or n₄≠n₁₂ or n₅≠n₁₃ or n₆≠n₁₄ or n₇≠n₁₅    or n₈≠n₁₆ holds} hold.”

or

-   “n₁>0 (n₁ is a real number greater than 0) and n₂>0 (n₂ is a real    number greater than 0) and n₃>0 (n₃ is a real number greater than 0)    and n₄>0 (n₄ is a real number greater than 0) and n₅>0 (n₅ is a real    number greater than 0) and n₆>0 (n₆ is a real number greater than 0)    and n₇>0 (n₇ is a real number greater than 0) and n₈>0 (n₈ is a real    number greater than 0) and n₉>0 (n₉ is a real number greater than 0)    and n₁₀>0 (n₁₀ is a real number greater than 0) and n₁₁>0 (n₁₁ is a    real number greater than 0) and n₁₂>0 (n₁₂ is a real number greater    than 0) and n₁₃>0 (n₁₃ is a real number greater than 0) and n₁₄>0    (n₁₄ is a real number greater than 0) and n₁₅>0 (n₁₅ is a real    number greater than 0) and n₁₆>0 (n₁₆ is a real number greater    than 0) hold, and-   {n₁≠n₂ and n₁≠n₃ and n₁≠n₄ and n₁≠n₅ and n₁≠n₆ and n₁≠n₇ and n₁≠n₈-   and n₂≠n₃ and n₂≠n₄ and n₂≠n₅ and n₂≠n₆ and n₂≠n₇ and n₂≠n₈-   and n₃≠n₄ and n₃≠n₅ and n 3≠n₆ and n₃≠n₇ and n₃≠n₈-   and n₄≠n₅ and n₄≠n₆ and n₄≠n₇ and n₄≠n₈-   and n₅≠n₆ and n₅≠n₇ and n₅≠n₈-   and n₆≠n₇ and n₆≠n₈-   and n₇≠n₈}-   and-   {n₉≠n₁₀ and n₉≠n₁₁ and n₉≠n₁₂ and n₉≠n₁₃ and n₉≠n₁₄ and n₉≠n₁₅ and    n₉≠n₁₆-   and n₁₀≠n₁₁ and n₁₀≠n₁₂ and n₁₀≠n₁₃ and n₁₀≠n₁₄ and n₁₀≠n₁₅ and    n₁₀≠n₁₆-   and n₁₁≠n₁₂ and n₁₁≠n₁₃ and n₁₁≠n₁₄ and n₁₁≠n₁₅ and n₁₁≠n₁₆-   and n₁₂≠n₁₃ and n₁₂≠n₁₄ and n₁₂≠n₁₅ and n₁₂≠n₁₆-   and n₁₃≠n₁₄ and n₁₃≠n₁₅ and n₁₃≠n₁₆-   and n₁₄≠n₁₅ and n₁₄≠n₁₆-   and n₁₅≠n₁₆}-   and-   {n₁≠n₉ or n₂≠n₁₀ or n₃≠n₁₁ or n₄≠n₁₂ or n₅≠n₁₃ or n₆≠n₁₄ or n₇≠n₁₅    or n₈≠n₁₆ holds},-   and-   {n₁=n₉ or n₂=n₁₀ or n₃=n₁₁ or n₄=n₁₂ or n₅=n₁₃ or n₆=n₁₄ or n₇=n₁₅    or n₈=n₁₆ holds} hold.”

In the in-phase I-orthogonal Q plane, coordinates of the 256 signalpoints (in FIG. 11, the mark “◯” indicates the signal point) for 256 QAMare expressed as follows:

-   (n₈×w_(256c), n₁₆×w_(256c)), (n₈×w_(256c), n₁₅×w_(256c)),    (n₈×w_(256c), n₁₄×w_(256c)), (n₈×w_(256c), n₁₃×w_(256c)),    (n₈×w_(256c), n₁₂×w_(256c)), (n₈×w_(256c), n₁₁×w_(256c)),    (n₈×w_(256c), n₁₀×w_(256c)), (n₈×w_(256c), n₉×w_(256c)),    (n₈×w_(256c), −n₁₆×w_(256c)), (n₈×w_(256c), −n₁₅×w_(256c)),    (n₈×w_(256c), −n₁₄×w_(256c)), (n₈×w_(256c), −n₁₃×w_(256c)),    (n₈×w_(256c), −n₁₂×w_(256c)), (n₈×w_(256c), −n₁₁×w_(256c)),    (n₈×w_(256c), −n₁₀×w_(256c)), (n₈×w_(256c), −n₉×w_(256c)),-   (n₇×w_(256c), n₁₆×w_(256c)), (n₇×w_(256c), n₁₅×w_(256c)),    (n₇×w_(256c), n₁₄×w_(256c)), (n₇×w_(256c), n₁₃×w_(256c)),    (n₇×w_(256c), n₁₂×w_(256c)), (n₇×w_(256c), n₁₁×w_(256c)),    (n₇×w_(256c), n₁₀×w_(256c)), (n₇×w_(256c), n₉×w_(256c)),    (n₇×w_(256c), −n₁₆×w_(256c)), (n₇×w_(256c), −n₁₅×w_(256c)),    (n₇×w_(256c), −n₁₄×w_(256c)), (n₇×w_(256c), −n₁₃×w_(256c)),    (n₇×w_(256c), −n₁₂×w_(256c)), (n₇×w_(256c), −n₁₁×w_(256c)),    (n₇×w_(256c), −n₁₀×w_(256c)), (n₇×w_(256c), −n₉×w_(256c)),-   (n₆×w_(256c), n₁₆×w_(256c)), (n₆×w_(256c), n₁₅×w_(256c)),    (n₆×w_(256c), n₁₄×w_(256c)), (n₆×w_(256c), n₁₃×w_(256c)),    (n₆×w_(256c), n₁₂×w_(256c)), (n₆×w_(256c), n₁₁×w_(256c)),    (n₆×w_(256c), n₁₀×w_(256c)), (n₆×w_(256c), n₉×w_(256c)),    (n₆×w_(256c), −n₁₆×w_(256c)), (n₆×w_(256c), −n₁₅×w_(256c)),    (n₆×w_(256c), −n₁₄×w_(256c)), (n₆×w_(256c), −n₁₃×w_(256c)),    (n₆×w_(256c), −n₁₂×w_(256c)), (n₆×w_(256c), −n₁₁×w_(256c)),    (n₆×w_(256c), −n₁₀×w_(256c)), (n₆×w_(256c), −n₉×w_(256c)),-   (n₅×w_(256c), n₁₆×w_(256c)), (n₅×w_(256c), n₁₅×w_(256c)),    (n₅×w_(256c), n₁₄×w_(256c)), (n₅×w_(256c), n₁₃×w_(256c)),    (n₅×w_(256c), n₁₂×w_(256c)), (n₅×w_(256c), n₁₁×w_(256c)),    (n₅×w_(256c), n₁₀×w_(256c)), (n₅×w_(256c), n₉×w_(256c)),    (n₅×w_(256c), −n₁₆×w_(256c)), (n₅×w_(256c), −n₁₅×w_(256c)),    (n₅×w_(256c), −n₁₄×w_(256c)), (n₅×w_(256c), −n₁₃×w_(256c)),    (n₅×w_(256c), −n₁₂×w_(256c)), (n₅×w_(256c), −n₁₁×w_(256c)),    (n₅×w_(256c), −n₁₀×w_(256c)), (n₅×w_(256c), −n₉×w_(256c)),-   (n₄×w_(256c), n₁₆×w_(256c)), (n₄×w_(256c), n₁₅×w_(256c)),    (n₄×w_(256c), n₁₄×w_(256c)), (n₄×w_(256c), n₁₃×w_(256c)),    (n₄×w_(256c), n₁₂×w_(256c)), (n₄×w_(256c), n₁₁×w_(256c)),    (n₄×w_(256c), n₁₀×w_(256c)), (n₄×w_(256c), n₉×w_(256c)),    (n₄×w_(256c), −n₁₆×w_(256c)), (n₄×w_(256c), −n₁₅×w_(256c)),    (n₄×w_(256c), −n₁₄×w_(256c)), (n₄×w_(256c), −n₁₃×w_(256c)),    (n₄×w_(256c), −n₁₂×w_(256c)), (n₄×w_(256c), −n₁₁×w_(256c)),    (n₄×w_(256c), −n₁₀×w_(256c)), (n₄×w_(256c), −n₉×w_(256c)),-   (n₃×w_(256c), n₁₆×w_(256c)), (n₃×w_(256c), n₁₅×w_(256c)),    (n₃×w_(256c), n₁₄×w_(256c)), (n₃×w_(256c), n₁₃×w_(256c)),    (n₃×w_(256c), n₁₂×w_(256c)), (n₃×w_(256c), n₁₁×w_(256c)),    (n₃×w_(256c), n₁₀×w_(256c)), (n₃×w_(256c), n₉×w_(256c)),    (n₃×w_(256c), −n₁₆×w_(256c)), (n₃×w_(256c), −n₁₅×w_(256c)),    (n₃×w_(256c), −n₁₄×w_(256c)), (n₃×w_(256c), −n₁₃×w_(256c)),    (n₃×w_(256c), −n₁₂×w_(256c)), (n₃×w_(256c), −n₁₁×w_(256c)),    (n₃×w_(256c), −n₁₀×w_(256c)), (n₃×w_(256c), −n₉×w_(256c)),-   (n₂×w_(256c), n₁₆×w_(256c)), (n₂×w_(256c), n₁₅×w_(256c)),    (n₂×w_(256c), n₁₄×w_(256c)), (n₂×w_(256c), n₁₃×w_(256c)),    (n₂×w_(256c), n₁₂×w_(256c)), (n₂×w_(256c), n₁₁×w_(256c)),    (n₂×w_(256c), n₁₀×w_(256c)), (n₂×w_(256c), n₉×w_(256c)),    (n₂×w_(256c), −n₁₆×w_(256c)), (n₂×w_(256c), −n₁₅×w_(256c)),    (n₂×w_(256c), −n₁₄×w_(256c)), (n₂×w_(256c), −n₁₃×w_(256c)),    (n₂×w_(256c), −n₁₂×w_(256c)), (n₂×w_(256c), −n₁₁×w_(256c)),    (n₂×w_(256c), −n₁₀×w_(256c)), (n₂×w_(256c), −n₉×w_(256c)),-   (n₁×w_(256c), n₁₆×w_(256c)), (n₁×w_(256c), n₁₅×w_(256c)),    (n₁×w_(256c), n₁₄×w_(256c)), (n₁×w_(256c), n₁₃×w_(256c)),    (n₁×w_(256c), n₁₂×w_(256c)), (n₁×w_(256c), n₁₁×w_(256c)),    (n₁×w_(256c), n₁₀×w_(256c)), (n₁×w_(256c), n₉×w_(256c)),    (n₁×w_(256c), −n₁₆×w_(256c)), (n₁×w_(256c), −n₁₅×w_(256c)),    (n₁×w_(256c), −n₁₄×w_(256c)), (n₁×w_(256c), −n₁₃×w_(256c)),    (n₁×w_(256c), −n₁₂×w_(256c)), (n₁×w_(256c), −n₁₁×w_(256c)),    (n₁×w_(256c), −n₁₀×w_(256c)), (n₁×w_(256c), −n₉×w_(256c)),-   (−n₈×w_(256c), n₁₆×w_(256c)), (−n₈×w_(256c), n₁₅×w_(256c)),    (−n₈×w_(256c), n₁₄×w_(256c)), (−n₈×w_(256c), n₁₃×w_(256c)),    (−n₈×w_(256c), n₁₂×w_(256c)), (−n₈×w_(256c), n₁₁×w_(256c)),    (−n₈×w_(256c), n₁₀×w_(256c)), (−n₈×w_(256c), n₉×w_(256c)),    (−n₈×w_(256c), −n₁₆×w_(256c)), (−n₈×w_(256c), −n₁₅×w_(256c)),    (−n₈×w_(256c), −n₁₄×w_(256c)), (−n₈×w_(256c), −n₁₃×w_(256c)),    (−n₈×w_(256c), −n₁₂×w_(256c)), (−n₈×w_(256c), −n₁₁×w_(256c)),    (−n₈×w_(256c), −n₁₀×w_(256c)), (−n₈×w_(256c), −n₉×w_(256c)),-   (−n₇×w_(256c), n₁₆×w_(256c)), (−n₇×w_(256c), n₁₅×w_(256c)),    (−n₇×w_(256c), n₁₄×w_(256c)), (−n₇×w_(256c), n₁₃×w_(256c)),    (−n₇×w_(256c), n₁₂×w_(256c)), (−n₇×w_(256c), n₁₁×w_(256c)),    (−n₇×w_(256c), n₁₀×w_(256c)), (−n₇×w_(256c), n₉×w_(256c)),    (−n₇×w_(256c), −n₁₆×w_(256c)), (−n₇×w_(256c), −n₁₅×w_(256c)),    (−n₇×w_(256c), −n₁₄×w_(256c)), (−n₇×w_(256c), −n₁₃×w_(256c)),    (−n₇×w_(256c), −n₁₂×w_(256c)), (−n₇×w_(256c), −n₁₁×w_(256c)),    (−n₇×w_(256c), −n₁₀×w_(256c)), (−n₇×w_(256c), −n₉×w_(256c)),-   (−n₆×w_(256c), n₁₆×w_(256c)), (−n₆×w_(256c), n₁₅×w_(256c)),    (−n₆×w_(256c), n₁₄×w_(256c)), (−n₆×w_(256c), n₁₃×w_(256c)),    (−n₆×w_(256c), n₁₂×w_(256c)), (−n₆×w_(256c), n₁₁×w_(256c)),    (−n₆×w_(256c), n₁₀×w_(256c)), (−n₆×w_(256c), n₉×w_(256c)),    (−n₆×w_(256c), −n₁₆×w_(256c)), (−n₆×w_(256c), −n₁₅×w_(256c)),    (−n₆×w_(256c), −n₁₄×w_(256c)), (−n₆×w_(256c), −n₁₃×w_(256c)),    (−n₆×w_(256c), −n₁₂×w_(256c)), (−n₆×w_(256c), −n₁₁×w_(256c)),    (−n₆×w_(256c), −n₁₀×w_(256c)), (−n₆×w_(256c), −n₉×w_(256c)),-   (−n₅×w_(256c), n₁₆×w_(256c)), (−n₅×w_(256c), n₁₅×w_(256c)),    (−n₅×w_(256c), n₁₄×w_(256c)), (−n₅×w_(256c), n₁₃×w_(256c)),    (−n₅×w_(256c), n₁₂×w_(256c)), (−n₅×w_(256c), n₁₁×w_(256c)),    (−n₅×w_(256c), n₁₀×w_(256c)), (−n₅×w_(256c), n₉×w_(256c)),    (−n₅×w_(256c), −n₁₆×w_(256c)), (−n₅×w_(256c), −n₁₅×w_(256c)),    (−n₅×w_(256c), −n₁₄×w_(256c)), (−n₅×w_(256c), −n₁₃×w_(256c)),    (−n₅×w_(256c), −n₁₂×w_(256c)), (−n₅×w_(256c), −n₁₁×w_(256c)),    (−n₅×w_(256c), −n₁₀×w_(256c)), (−n₅×w_(256c), −n₉×w_(256c)),-   (−n₄×w_(256c), n₁₆×w_(256c)), (−n₄×w_(256c), n₁₅×w_(256c)),    (−n₄×w_(256c), n₁₄×w_(256c)), (−n₄×w_(256c), n₁₃×w_(256c)),    (−n₄×w_(256c), n₁₂×w_(256c)), (−n₄×w_(256c), n₁₁×w_(256c)),    (−n₄×w_(256c), n₁₀×w_(256c)), (−n₄×w_(256c), n₉×w_(256c)),    (−n₄×w_(256c), −n₁₆×w_(256c)), (−n₄×w_(256c), −n₁₅×w_(256c)),    (−n₄×w_(256c), −n₁₄×w_(256c)), (−n₄×w_(256c), −n₁₃×w_(256c)),    (−n₄×w_(256c), −n₁₂×w_(256c)), (−n₄×w_(256c), −n₁₁×w_(256c)),    (−n₄×w_(256c), −n₁₀×w_(256c)), (−n₄×w_(256c), −n₉×w_(256c)),-   (−n₃×w_(256c), n₁₆×w_(256c)), (−n₃×w_(256c), n₁₅×w_(256c)),    (−n₃×w_(256c), n₁₄×w_(256c)), (−n₃×w_(256c), n₁₃×w_(256c)),    (−n₃×w_(256c), n₁₂×w_(256c)), (−n₃×w_(256c), n₁₁×w_(256c)),    (−n₃×w_(256c), n₁₀×w_(256c)), (−n₃×w_(256c), n₉×w_(256c)),    (−n₃×w_(256c), −n₁₆×w_(256c)), (−n₃×w_(256c), −n₁₅×w_(256c)),    (−n₃×w_(256c), −n₁₄×w_(256c)), (−n₃×w_(256c), −n₁₃×w_(256c)),    (−n₃×w_(256c), −n₁₂×w_(256c)), (−n₃×w_(256c), −n₁₁×w_(256c)),    (−n₃×w_(256c), −n₁₀×w_(256c)), (−n₃×w_(256c), −n₉×w_(256c)),-   (−n₂×w_(256c), n₁₆×w_(256c)), (−n₂×w_(256c), n₁₅×w_(256c)),    (−n₂×w_(256c), n₁₄×w_(256c)), (−n₂×w_(256c), n₁₃×w_(256c)),    (−n₂×w_(256c), n₁₂×w_(256c)), (−n₂×w_(256c), n₁₁×w_(256c)),    (−n₂×w_(256c), n₁₀×w_(256c)), (−n₂×w_(256c), n₉×w_(256c)),    (−n₂×w_(256c), −n₁₆×w_(256c)), (−n₂×w_(256c), −n₁₅×w_(256c)),    (−n₂×w_(256c), −n₁₄×w_(256c)), (−n₂×w_(256c), −n₁₃×w_(256c)),    (−n₂×w_(256c), −n₁₂×w_(256c)), (−n₂×w_(256c), −n₁₁×w_(256c)),    (−n₂×w_(256c), −n₁₀×w_(256c)), (−n₂×w_(256c), −n₉×w_(256c)),-   (−n₁×w_(256c), n₁₆×w_(256c)), (−n₁×w_(256c), n₁₅×w_(256c)),    (−n₁×w_(256c), n₁₄×w_(256c)), (−n₁×w_(256c), n₁₃×w_(256c)),    (−n₁×w_(256c), n₁₂×w_(256c)), (−n₁×w_(256c), n₁₁×w_(256c)),    (−n₁×w_(256c), n₁₀×w_(256c)), (−n₁×w_(256c), n₉×w_(256c)),    (−n₁×w_(256c), −n₁₆×w_(256c)), (−n₁×w_(256c), −n₁₅×w_(256c)),    (−n₁×w_(256c), −n₁₄×w_(256c)), (−n₁×w_(256c), −n₁₃×w_(256c)),    (−n₁×w_(256c), −n₁₂×w_(256c)), (−n₁×w_(256c), −n₁₁×w_(256c)),    (−n₁×w_(256c), −n₁₀×w_(256c)), (−n₁×w_(256c), −n₉×w_(256c)), where    w_(256c) is a real number greater than 0.

In FIG. 11, the bits (input bits) to be transmitted are set to b0, b1b2, b3, b4, b5, b6, and b7. For example, the bits to be transmitted(b0,b1,b2,b3,b4,b5,b6,b7)=(0,0,0,0,0,0,0,0) are mapped in signal pointH901 of FIG. 11 and (I,Q)=(n₈×w_(256c), n₁₆×w_(256c)) is obtained, whereI and Q are the in-phase component and the orthogonal component of thepost-mapping baseband signal, respectively.

In FIG. 11, in-phase component I and orthogonal component Q of thepost-mapping baseband signal (in 256 QAM) are decided based on the bitsto be transmitted (b0,b1,b2,b3,b4,b5,b6,b7). An example of therelationship between a set of b0, b1 b2, b3, b4, b5, b6, and b7(00000000 to 11111111) and the coordinates of the signal point isindicated in FIG. 11. The values of the sets of b0, b1, b2, b3, b4, b5,b6, and b7 (00000000 to 11111111) are indicated immediately below the256 signal points (the marks “◯” in FIG. 11) of 256 QAM:

-   (n₈×w_(256c), n₁₆×w_(256c)), (n₈×w_(256c), n₁₅×w_(256c)),    (n₈×w_(256c), n₁₄×w_(256c)), (n₈×w_(256c), n₁₃×w_(256c)),    (n₈×w_(256c), n₁₂×w_(256c)), (n₈×w_(256c), n₁₁×w_(256c)),    (n₈×w_(256c), n₁₀×w_(256c)), (n₈×w_(256c), n₉×w_(256c)),    (n₈×w_(256c), −n₁₆×w_(256c)), (n₈×w_(256c), −n₁₅×w_(256c)),    (n₈×w_(256c), −n₁₄×w_(256c)), (n₈×w_(256c), −n₁₃×w_(256c)),    (n₈×w_(256c), −n₁₂×w_(256c)), (n₈×w_(256c), −n₁₁×w_(256c)),    (n₈×w_(256c), −n₁₀×w_(256c)), (n₈×w_(256c), −n₉×w_(256c)),-   (n₇×w_(256c), n₁₆×w_(256c)), (n₇×w_(256c), n₁₅×w_(256c)),    (n₇×w_(256c), n₁₄×w_(256c)), (n₇×w_(256c), n₁₃×w_(256c)),    (n₇×w_(256c), n₁₂×w_(256c)), (n₇×w_(256c), n₁₁×w_(256c)),    (n₇×w_(256c), n₁₀×w_(256c)), (n₇×w_(256c), n₉×w_(256c)),    (n₇×w_(256c), −n₁₆×w_(256c)), (n₇×w_(256c), −n₁₅×w_(256c)),    (n₇×w_(256c), −n₁₄×w_(256c)), (n₇×w_(256c), −n₁₃×w_(256c)),    (n₇×w_(256c), −n₁₂×w_(256c)), (n₇×w_(256c), −n₁₁×w_(256c)),    (n₇×w_(256c), −n₁₀w_(256c)), (n₇×w_(256c), −n₉×w_(256c)),-   (n₆×w_(256c), n₁₆×w_(256c)), (n₆×w_(256c), n₁₅×w_(256c)),    (n₆×w_(256c), n₁₄×w_(256c)), (n₆×w_(256c), n₁₃×w_(256c)),    (n₆×w_(256c), n₁₂×w_(256c)), (n₆×w_(256c), n₁₁×w_(256c)),    (n₆×w_(256c), n₁₀×w_(256c)), (n₆×w_(256c), n₆×w_(256c)),    (n₆×w_(256c), −n₁₆×w_(256c)), (n₆×w_(256c), −n₁₅×w_(256c)),    (n₆×w_(256c), −n₁₄×w_(256c)), (16×w_(256c), −n₁₃×w_(256c)),    (n₆×w_(256c), −n₁₂×w_(256c)), (n₆×w_(256c), −n₁₁×w_(256c)),    (n₆×w_(256c), −n₁ O×w_(256c)), (n₆×w_(256c), −n₉×w_(256c)),-   (n₅×w_(256c), n₁₆×w_(256c)), (n₅×w_(256c), n₁₅×w_(256c)),    (n₅×w_(256c), n₁₄×w_(256c)), (n₅×w_(256c), n₁₃×w_(256c)),    (n₅×w_(256c), n₁₂×w_(256c)), (n₅×w_(256c), n₁₁×w_(256c)),    (n₅×w_(256c), n₁₀×w_(256c)), (n₅×w_(256c), n₉×w_(256c)),    (n₅×w_(256c), −n₁₆×w_(256c)), (n₅×w_(256c), −n₁₅×w_(256c)),    (n₅×w_(256c), −n₁₄×w_(256c)), (n₅×w_(256c), −n₁₃×w_(256c)),    (n₅×w_(256c), −n₁₂×w_(256c)), (n₅×w_(256c), −n₁₁×w_(256c)),    (n₅×w_(256c), −n₁₀×w_(256c)), (n₅×w_(256c), −n₉×w_(256c)),-   (n₄×w_(256c), n₁₆×w_(256c)), (n₄×w_(256c), n₁₅×w_(256c)),    (n₄×w_(256c), n₁₄×w_(256c)), (n₄×w_(256c), n₁₃×w_(256c)),    (n₄×w_(256c), n₁₂×w_(256c)), (n₄×w_(256c), n₁₁×w_(256c)),    (n₄×w_(256c), n₁₀×w_(256c)), (n₄×w_(256c), n₉×w_(256c)),    (n₄×w_(256c), −n₁₆×w_(256c)), (n₄×w_(256c), −n₁₅×w_(256c)),    (n₄×w_(256c), −n₁₄×w_(256c)), (n₄×w_(256c), −n₁₃×w_(256c)),    (n₄×w_(256c), −n₁₂×w_(256c)), (n₄×w_(256c), −n₁₁×w_(256c)),    (n₄×w_(256c), −n₁₀×w_(256c)), (n₄×w_(256c), −n₉×w_(256c)),-   (n₃×w_(256c), n₁₆×w_(256c)), (n₃×w_(256c), n₁₅×w_(256c)),    (n₃×w_(256c), n₁₄×w_(256c)), (n₃×w_(256c), n₁₃×w_(256c)),    (n₃×w_(256c), n₁₂×w_(256c)), (n₃×w_(256c), n₁₁×w_(256c)),    (n₃×w_(256c), n₁₀×w_(256c)), (n₃×w_(256c), n₉×w_(256c)),    (n₃×w_(256c), −n₁₆×w_(256c)), (n₃×w_(256c), −n₁₅×w_(256c)),    (n₃×w_(256c), −n₁₄×w_(256c)), (n₃×w_(256c), −n₁₃×w_(256c)),    (n₃×w_(256c), −n₁₂×w_(256c)), (n₃×w_(256c), −n₁₁×w_(256c)),    (n₃×w_(256c), −n₁₀×w_(256c)), (n₃×w_(256c), −n₉×w_(256c)),-   (n₂×w_(256c), n₁₆×w_(256c)), (n₂×w_(256c), n₁₅×w_(256c)),    (n₂×w_(256c), n₁₄×w_(256c)), (n₂×w_(256c), n₁₃×w_(256c)),    (n₂×w_(256c), n₁₂×w_(256c)), (n₂×w_(256c), n₁₁×w_(256c)),    (n₂×w_(256c), n₁₀×w_(256c)), (n₂×w_(256c), n₉×w_(256c)),    (n₂×w_(256c), −n₁₆×w_(256c)), (n₂×w_(256c), −n₁₅×w_(256c)),    (n₂×w_(256c), −n₁₄×w_(256c)), (n₂×w_(256c), −n₁₃×w_(256c)),    (n₂×w_(256c), −n₁₂×w_(256c)), (n₂×w_(256c), −n₁₁×w_(256c)),    (n₂×w_(256c), −n₁₀×w_(256c)), (n₂×w_(256c), −n₉×w_(256c)),-   (n₁×w_(256c), n₁₆×w_(256c)), (n₁×w_(256c), n₁₅×w_(256c)),    (n₁×w_(256c), n₁₄×w_(256c)), (n₁×w_(256c), n₁₃×w_(256c)),    (n₁×w_(256c), n₁₂×w_(256c)), (n₁×w_(256c), n₁₁×w_(256c)),    (n₁×w_(256c), n₁₀×w_(256c)), (n₁×w_(256c), n₉×w_(256c)),    (n₁×w_(256c), −n₁₆×w_(256c)), (n₁×w_(256c), −n₁₅×w_(256c)),    (n₁×w_(256c), −n₁₄×w_(256c)), (n₁×w_(256c), −n₁₃×w_(256c)),    (n₁×w_(256c), −n₁₂×w_(256c)), (n₁×w_(256c), −n₁₁×w_(256c)),    (n₁×w_(256c), −n₁₀×w_(256c)), (n₁×w_(256c), −n₉×w_(256c)),-   (−n₈×w_(256c), n₁₆×w_(256c)), (−n₈×w_(256c), n₁₅×w_(256c)),    (−n₈×w_(256c), n₁₄×w_(256c)), (−n₈×w_(256c), n₁₃×w_(256c)),    (−n₈×w_(256c), n₁₂×w_(256c)), (−n₈×w_(256c), n₁₁×w_(256c)),    (−n₈×w_(256c), n₁₀×w_(256c)), (−n₈×w_(256c), n₉×w_(256c)),    (−n₈×w_(256c), −n₁₆×w_(256c)), (−n₈×w_(256c), −n₁₅×w_(256c)),    (−n₈×w_(256c), −n₁₄×w_(256c)), (−n₈×w_(256c), −n₁₃×w_(256c)),    (−n₈×w_(256c), −n₁₂×w_(256c)), (−n₈×w_(256c), −n₁₁×w_(256c)),    (−n₈×w_(256c), −n₁₀×w_(256c)), (−n₈×w_(256c), −n₉×w_(256c)),-   (−n₇×w_(256c), n₁₆×w_(256c)), (−n₇×w_(256c), n₁₅×w_(256c)),    (−n₇×w_(256c), n₁₄×w_(256c)), (−n₇×w_(256c), n₁₃×w_(256c)),    (−n₇×w_(256c), n₁₂×w_(256c)), (−n₇×w_(256c), n₁₁×w_(256c)),    (−n₇×w_(256c), n₁₀×w_(256c)), (−n₇×w_(256c), n₉×w_(256c)),    (−n₇×w_(256c), −n₁₆×w_(256c)), (−n₇×w_(256c), −n₁₅×w_(256c)),    (−n₇×w_(256c), −n₁₄×w_(256c)), (−n₇×w_(256c), −n₁₃×w_(256c)),    (−n₇×w_(256c), −n₁₂×w_(256c)), (−n₇×w_(256c), −n₁₁×w_(256c)),    (−n₇×w_(256c), −n₁₀×w_(256c)), (−n₇×w_(256c), −n₉×w_(256c)),-   (−n₆×w_(256c), n₁₆×w_(256c)), (−n₆×w_(256c), n₁₅×w_(256c)),    (−n₆×w_(256c), n₁₄×w_(256c)), (−n₆×w_(256c), n₁₃×w_(256c)),    (−n₆×w_(256c), n₁₂×w_(256c)), (−n₆×w_(256c), n₁₁×w_(256c)),    (−n₆×w_(256c), n₁₀×w_(256c)), (−n₆×w_(256c), n₉×w_(256c)),    (−n₆×w_(256c), −n₁₆×w_(256c)), (−n₆×w_(256c), −n₁₅×w_(256c)),    (−n₆×w_(256c), −n₁₄×w_(256c)), (−n₆×w_(256c), −n₁₃×w_(256c)),    (−n₆×w_(256c), −n₁₂×w_(256c)), (−n₆×w_(256c), −n₁₁×w_(256c)),    (−n₆×w_(256c), −n₁₀×w_(256c)), (−n₆×w_(256c), −n₉×X w_(256c)),-   (−n₅×w_(256c), n₁₆×w_(256c)), (−n₅×w_(256c), n₁₅×w_(256c)),    (−n₅×w_(256c), n₁₄×w_(256c)), (−n₅×w_(256c), n₁₃×w_(256c)),    (−n₅×w_(256c), n₁₂×w_(256c)), (−n₅×w_(256c), n₁₁×w_(256c)),    (−n₅×w_(256c), n₁₀×w_(256c)), (−n₅×w_(256c), n₉×w_(256c)),    (−n₅×w_(256c), −n₁₆×w_(256c)), (−n₅×w_(256c), −n₁₅×w_(256c)),    (−n₅×w_(256c), −n₁₄×w_(256c)), (−n₅×w_(256c), −n₁₃×w_(256c)),    (−n₅×w_(256c), −n₁₂×w_(256c)), (−n₅×w_(256c), −n₁₁×w_(256c)),    (−n₅×w_(256c), −n₁₀×w_(256c)), (−n₅×w_(256c), −n₉×w_(256c)),-   (−n₄×w_(256c), n₁₆×w_(256c)), (−n₄×w_(256c), n₁₅×w_(256c)),    (−n₄×w_(256c), n₁₄×w_(256c)), (−n₄×w_(256c), n₁₃×w_(256c)),    (−n₄×w_(256c), n₁₂×w_(256c)), (−n₄×w_(256c), n₁₁×w_(256c)),    (−n₄×w_(256c), n₁₀×w_(256c)), (−n₄×w_(256c), n₉×w_(256c)),    (−n₄×w_(256c), −n₁₆×w_(256c)), (−n₄×w_(256c), −n₁₅×w_(256c)),    (−n₄×w_(256c), −n₁₄×w_(256c)), (−n₄×w_(256c), −n₁₃×w_(256c)),    (−n₄×w_(256c), −n₁₂×w_(256c)), (−n₄×w_(256c), −n₁₁×w_(256c)),    (−n₄×w_(256c), −n₁₀×w_(256c)), (−n₄×w_(256c), −n₉×w_(256c)),-   (−n₃×w_(256c), n₁₆×w_(256c)), (−n₃×w_(256c), n₁₅×w_(256c)),    (−n₃×w_(256c), n₁₄×w_(256c)), (−n₃×w_(256c), n₁₃×w_(256c)),    (−n₃×w_(256c), n₁₂×w_(256c)), (−n₃×w_(256c), n₁₁×w_(256c)),    (−n₃×w_(256c), n₁₀×w_(256c)), (−n₃×w_(256c), n₉×w_(256c)),    (−n₃×w_(256c), −n₁₆×w_(256c)), (−n₃×w_(256c), −n₁₅×w_(256c)),    (−n₃×w_(256c), −n₁₄×w_(256c)), (−n₃×w_(256c), −n₁₃×w_(256c)),    (−n₃×w_(256c), −n₁₂×w_(256c)), (−n₃×w_(256c), −n₁₁×w_(256c)),    (−n₃×w_(256c), −n₁₀×w_(256c)), (−n₃×w_(256c), −n₉×w_(256c)),-   (−n₁₂×w_(256c), n₁₆×w_(256c)), (−n₂×w_(256c), n₁₅×w_(256c)),    (−n₂×w_(256c), n₁₄×w_(256c)), (−n₂×w_(256c), n₁₃×w_(256c)),    (−n₂×w_(256c), n₁₂×w_(256c)), (−n₂×w_(256c), n₁₁×w_(256c)),    (−n₂×w_(256c), n₁₀×w_(256c)), (−112×w_(256c), n₉×w_(256c)),    (−n₂×w_(256c), −n₁₆×w_(256c)), (−n₂×w_(256c), −n₁₅×w_(256c)),    (−n₂×w_(256c), −n₁₄×w_(256c)), (−n₂×w_(256c), −n₁₃×w_(256c)),    (−n₂×w_(256c), −n₁₂×w_(256c)), (−n₂×w_(256c), −n₁₁×w_(256c)),    (−n₂×w_(256c), −n₁₀×w_(256c)), (−n₂×w_(256c), −n₉×w_(256c)),-   (−n₁×w_(256c), n₁₆×w_(256c)), (−n₁×w_(256c), n₁₅×w_(256c)),    (−n₁×w_(256c), n₁₄×w_(256c)), (−n₁×w_(256c), n₁₃×w_(256c)),    (−n₁×w_(256c), n₁₂×w_(256c)), (−n₁×w_(256c), n₁₁×w_(256c)),    (−n₁×w_(256c), n₁×w_(256c)), (−n₁×w_(256c), n₉×w_(256c)),    (−n₁×w_(256c), −n₁₆×w_(256c)), (−n₁×w_(256c), −n₁₅×w_(256c)),    (−n₁×w_(256c), −n₁₄×w_(256c), (−n₁×w_(256c), −n₁₃×w_(256c)),    (−n₁×w_(256c), −n₁₂×w_(256c)), (−n₁×w_(256c), −n₁₁×w_(256c)),    (−n₁×w_(256c), −n₁₀×w_(256c)), (−n₁×w_(256c), −n₉×w_(256c)).    The coordinates in the in-phase I-orthogonal Q plane of the signal    point (“◯”) immediately above the set of b0, b1, b2, b3, b4, b5, b6,    and b7 (00000000 to 11111111) serve as in-phase component I and    orthogonal component Q of the post-mapping baseband signal. The    relationship between the set of b0, b1, b2, b3, b4, b5, b6, and b7    (00000000 to 11111111) in 256 QAM and the coordinates of the signal    point is not limited to that illustrated in FIG. 11.

The 256 signal points in FIG. 11 are referred to as “signal point 1”,“signal point 2”, . . . , “signal point 255”, and “signal point 256”(because 256 signal points exist, “signal point 1” to “signal point 256”exist). Di is a distance between “signal point i” and an origin in thein-phase I-orthogonal Q plane. w_(256c) is given as follows.

[Mathematical  formula  9] $\begin{matrix}{w_{256c} = \frac{z}{\sqrt{\frac{\sum\limits_{i = 1}^{256}\; D_{i}^{2}}{256}}}} & ( {{Equation}\mspace{14mu} 9} )\end{matrix}$

From (Equation 9), an average power of the post-mapping baseband signalis z².

Hereinafter, the 256 QAM mapping method is referred to as “256 QAMmapping method #3”.

The mapping method in each modulation scheme is as described above.Detailed usage of the method in the transmission device is describedlater.

A configuration of the transmission device will be described below.

Referring to FIG. 12, data H1001 and control signal H1012 are input tomapper H1002. Data H1001 is obtained after the pieces of processing suchas error correction coding and interleaving (data rearrangement) areperformed on the information. Mapper H1002 sets a modulation scheme ofpost-mapping signal s1 and a modulation scheme of post-mapping signal s2based on control signal H1012, performs the mapping on data H1001, andoutput post-mapping signal s1(t) (H1003A) and post-mapping signal s2(t)(H1003B) (signal s1(t) and signal s2(t) are complex numbers). Signals s1and s2 may be a function of frequency f or a function of time t andfrequency f (accordingly, the output may be expressed as signals s1(f)and s2(f) or signals s1(t, f) and s2(t, f)). In this case, for example,it is assumed that signals s1 and s2 are the function of time t.

Post-mapping signal s1(t) (H1003A) and control signal H1012 are input topower changer H1004A, and power changer H1004A sets coefficient u (u isa real number but not zero (u≠0)) based on control signal H1012,multiplies post-mapping signal s1(t) by coefficient u, and outputspost-power-change signal H1005A (x1(t)=u×s1(t)) (post-power-changesignal H1005A is set to x1(t)).

Post-mapping signal s2(t) (H1003B) and control signal H1012 are input topower changer H1004B, and power changer H1004B sets coefficient v (v isa real number but not zero (v≠0)) based on control signal H1012,multiplies post-mapping signal s2(t) by coefficient v, and outputspost-power-change signal H1005B (x2(t)=v×s2(t)) (post-power-changesignal H1005B is set to x2(t)).

Power changer H1004A and power changer H1004B may directly output thepost-mapping signal of the input signal without changing power (at thispoint, u=1.0 and v=1.0 are obtained). In the case that the power changeis omitted, power changer H1004A and power changer H1004B may beeliminated from the transmission device in FIG. 12 (the same holds truefor FIG. 13).

Post-power-change signal H1005A (x1(t)), post-power-change signal H1005B(x2(t)), and control signal H1012 are input to weighting compositionpart H1006, and weighting composition part H1006 sets 2×2 matrix(pre-coding matrix) W including a complex number as an element based oncontrol signal H1012, multiplies matrix W by post-power-change signalH1005A (x1(t)) and post-power-change signal H1005B (x2(t)) (pre-coding),and outputs post-weighting-composition signal z1′(t) (H1007A) andpost-weighting-composition signal z2′(t) (H1007B).

Matrix (pre-coding matrix) W is given by the following equation.

[Mathematical  formula  10] $\begin{matrix}{W = \begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 10} )\end{matrix}$

Elements w11, w12, w21, and w22 may be or does not need to be a functionof time t. Elements w11, w12, w21, and w22 may be a real number or acomplex number.

Post-weighting-composition signal z1′(t) (H1007A) andpost-weighting-composition signal z2′(t) (H1007B) are given by thefollowing equation.

[Mathematical  formula  11] $\begin{matrix}{\begin{pmatrix}{z\; 1^{\prime}(t)} \\{z\; 2^{\prime}(t)}\end{pmatrix} = {\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}{x\; 1(t)} \\{x\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 11} )\end{matrix}$

Post-weighting-composition signal z2′(t) (H1007B) and control signalH1012 are input to phase changer H1008, and phase changer H1008 setsregularly changing phase change value θ(t) based on control signalH1012, performs a phase change on post-weighting-composition signalz2′(t) (H1007B), and outputs post-phase-change signal H1009 (z2″(t)).Accordingly, post-phase-change signal H1009 (z2″(t)) is given by thefollowing equation.

[Mathematical formula 12]

z2″(t)=e ^(jθ(t)) ×z2″(t)   (Equation 12)

j is an imaginary unit. Although phase change value θ(t) is dealt withas the function of time t, phase change value θ may be the function offrequency f or the function of frequency f and time t. The phase changeis described later.

Post-weighting-composition signal z1′(t) (H1007A) and control signalH1012 are input to power changer H1010A, and power changer H1010A setscoefficient a (a is a real number but not zero (a≠0)) based on controlsignal H1012, multiplies post-weighting-composition signal z1′(t)(H1007A) by coefficient a, and outputs post-power-change signal H1011A(z1(t)=a×z1′(t)) (post-power-change signal H1011A is set to z1(t)).

Post-phase-change signal H1009 (z2″(t)) and control signal H1012 areinput to power changer H1010B, and power changer H1010B sets coefficientb (b is a real number but not zero (b≠0)) based on control signal H1012,multiplies post-phase-change signal H1009 (z2″(t)) by coefficient b, andoutputs post-power-change signal H1011B (z2(t)=b×z2″(t))(post-power-change signal H1011B is set to z2(t)).

Power changer H1010A and power changer H1010B may directly output thepost-mapping signal of the input signal without changing power (at thispoint, a=1.0 and b=1.0 are obtained). In the case that power change isomitted, power changer H1010A and power changer H1010B may be eliminatedfrom the transmission device in FIG. 12 (the same holds true for FIG.13).

Therefore, a relationship between signals s1(t) and s2(t) and signalsz1(t) and z2(t) are given as follows.

     [Mathematical  formula  13] $\begin{matrix}{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 13} )\end{matrix}$

(Equation 14) is equivalent to (Equation 13).

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 14} \rbrack} & \; \\{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 14} )\end{matrix}$

In order to obtain (Equation 14), positions of phase changer H1008 andpower changer H1010B are replaced with each other in FIG. 12. FIG. 13illustrates the configuration after the replacement. The detaileddescription of the transmission device in FIG. 13 is omitted because thetransmission device in FIG. 13 performs (Equation 14) similarly to thetransmission device in FIG. 12. In the operation of FIG. 13, “phasechanger H1008 performs the phase change on the input signal and outputsthe post-phase-change signal” and “power changer H1010B performs thepower change on the input signal and outputs the post-power-changesignal”.

z1(t) and z2(t) are transmitted from different antennas at the sameclock time and the same frequency (common frequency).

Although z1(t) and z2(t) are the functions of time t, z1(t) and z2(t)may be the function of frequency f or the function of time t andfrequency f (accordingly, the output may be expressed as z1(f) and z2(f)or z1(t, f) and z2(t, f)). In this case, for example, the output isdescribed as the function of time t.

Therefore, z1(t), z2(t), z1′(t), z2′(t), and z2″(t) are also thefunction of time t. However, z1(t), z2(t), z1′(t), z2′(t), and z2″(t)may be the function of frequency f or the function of time t andfrequency f.

FIG. 14 illustrates a configuration of signal processing after thesignal processing in FIG. 12 or 13 is performed. Modulated signalH1221A, pilot symbol signal H1222A, control information symbol signalH1223A, and control signal H1212 are input to inserter H1224A. InserterH1224A generates baseband signal H1225A based on a frame configurationusing modulated signal H1221A, pilot symbol signal H1222A, and controlinformation symbol signal H1223A based on information about thetransmission method and frame configuration included in control signalH1212, and outputs baseband signal H1225A. Modulated signal H1221Acorresponds to z1(t) in FIG. 12 or 13.

Similarly, modulated signal H1221B, pilot symbol signal H1222B, controlinformation symbol signal H1223B, and control signal H1212 are input toinserter H1224B. Inserter H1224B generates baseband signal H1225B basedon a frame configuration using modulated signal H1221B, pilot symbolsignal H1222B, and control information symbol signal H1223B based oninformation about the transmission method and frame configurationincluded in control signal H1212, and outputs baseband signal H1225B.Modulated signal H1221B corresponds to z2(t) in FIG. 12 or 13.

Baseband signal H1225A and control signal H1212 are input to radio partH1226A, radio part H1226A generates transmission signal H1226A byperforming an inverse Fourier transform or pieces of processing such asan orthogonal modulation, frequency conversion, and amplification basedon control signal H1212 when, for example, an OFDM (Orthogonal FrequencyDivision Multiplexing) scheme is used, and radio part H1226A outputstransmission signal H1226A. Transmission signal H1226A is output fromantenna H1228A as a radio wave.

Similarly, baseband signal H1225B and control signal H1212 are input toradio part H1226B, radio part H1226B generates transmission signalH1226B by performing the inverse Fourier transform or the pieces ofprocessing such as the orthogonal modulation, the frequency conversion,and the amplification based on control signal H1212 when, for example,the OFDM scheme is used, and radio part H1226B outputs transmissionsignal H1226B. Transmission signal H1226B is output from antenna H1228Bas a radio wave.

FIG. 15 illustrates an example of a frame configuration of modulatedsignals which are transmitted through antennas, including z1(t) andz2(t) in FIGS. 12 and 13. In FIG. 15, the horizontal axis indicates thefrequency (carrier), and the vertical axis indicates the time. Forconvenience, the control information symbol is not illustrated in theframe configuration of FIG. 15.

FIG. 15 illustrates the frame configuration of carrier 1 to carrier 36and clock time $1 to clock time $11. In FIG. 15, H1301 designates apilot symbol (conforming to a rule of group 1), H1302 designates a pilotsymbol (conforming to a rule of group 2), and H1303 designates a datasymbol.

Transmission signal H1227A in FIG. 14 has the frame configuration havingsymbols including the data symbols and pilot symbols as illustrated inFIG. 15, and transmission signal H1227A is transmitted from antennaH1228A. At this point, data symbol H1303 is the symbol corresponding toz1(t), and includes the s1(t) component and the s2(t) component(however, sometimes data symbol H1303 includes only one of the s1(t)component and the s2(t) component depending on the pre-coding matrix).

Transmission signal H1227B in FIG. 14 has the frame configuration havingsymbols including the data symbols and pilot symbols as illustrated inFIG. 15, and transmission signal H1227B is transmitted from antennaH1228B. At this point, data symbol H1303 is the symbol corresponding toz2(t), and includes the s1(t) component and the s2(t) component(however, sometimes data symbol H1303 includes only one of the s1(t)component and the s2(t) component depending on the pre-coding matrix).

The pilot symbol in the frame configuration of transmission signalH1227A and the pilot symbol in the frame configuration of transmissionsignal H1227B are not limited to the same configuration (do notnecessarily have the same in-phase component and the same orthogonalcomponent), but each of transmission signals H1227A and H1227B mayinclude the pilot symbol conforming to a certain rule.

The frame configuration is not limited to that illustrated in FIG. 15,but may include a control information symbol including information onthe transmission method, the modulation scheme, and the error correctionmethod.

The frame configuration may be constructed with the pilot symbol and anull symbol (in-phase component I=0 and orthogonal component Q=0). Forexample, in the frame configuration, transmission signal H1227B maytransmit the null symbol using a carrier in which transmission signalH1227A transmits the pilot symbol at a clock time at which transmissionsignal H1227A transmits the pilot symbol. In contrast, in the frameconfiguration, transmission signal H1227A may transmit the null symbolusing a carrier in which transmission signal H1227B transmits the pilotsymbol at a clock time at which transmission signal H1227B transmits thepilot symbol.

In the frame configuration, the pilot symbol may have another differentconfiguration. It is necessary only to obtain a channel fluctuation oftransmission signal H1227A and a channel fluctuation of transmissionsignal H1227B in the reception device.

FIG. 16 illustrates a relationship between the transmission device andthe reception device of the exemplary embodiment. The operation of thetransmission device is described above. The operation of the receptiondevice will be described below.

FIG. 16 illustrates transmission device H1401 and reception deviceH1402. In FIG. 16, assuming that r1 is a reception signal of antenna RX1of the reception device, that r2 is a reception signal of antenna RX2,and that h11, h12, h21, and h22 are a factor of radio wave propagation(channel fluctuation) between the antennas of the transmitter andreceiver, the following equation holds.

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 15} \rbrack} & \; \\{\begin{pmatrix}{r\; 1(t)} \\{r\; 2(t)}\end{pmatrix} = {{\begin{pmatrix}{h_{11}(t)} & {h_{12}(t)} \\{h_{21}(t)} & {h_{22}(t)}\end{pmatrix}\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(t)} \\{n\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 15} )\end{matrix}$

In (Equation 15), n1 and n2 are noises.

In (Equation 15), each variable is the function of time t.Alternatively, each variable may be the function of frequency f or thefunction of time t and frequency f (in this case, each variable is thefunction of time t by way of example).

Channel estimator H1403A in FIG. 16 estimates h11(t) and h12(t) in(Equation 15). Therefore, channel estimator H1403A estimates values ofh11(t) and h12(t) in (Equation 15) using, for example, the pilot symbolin FIG. 15. Channel estimator H1403B in FIG. 16 estimates h21(t) andh22(t) in (Equation 15). Therefore, channel estimator H1403B estimatesvalues of h21(t) and h22(t) in (Equation 15) using, for example, thepilot symbol in FIG. 15.

Signal processor H1404 in FIG. 16 obtains a logarithmic likelihood ratioof each bit of the data transmitted by the transmission device using therelationship of (Equation 15). Then, signal processor H1404 performspieces of processing such as deinterleaving and error correctiondecoding to obtain reception information.

An example of a way to switch the mapping method, pre-coding matrix, andphase change of s1 and s2 in FIGS. 12 and 13 will be described below.

First, a way to provide phase change value θ(t) in (Equation 12) will bedescribed. In symbol number i (i is an integer of 0 or more), a valuethat can be taken by phase change value θ(i) is N kinds (N is an integerof 2 or more) of phase values. At this point, the N kinds of phasevalues are expressed by Phase[k] (k is an integer of 0 to N−1 and 0radian≤Phase[k]<2π radian). All the N kinds of phase values of Phase[k]are used in phase change value θ(i). The following condition holds,which allows the reception device to obtain the high data receptionquality.

<Condition #1>

Assuming that x is an integer of 0 to N−1, that y is an integer of 0 toN−1, and that x≠y holds, Phase[x]≠Phase[y] holds in all integers x and ysatisfying these assumptions.

Additionally, the following condition may be satisfied.

<Condition #2>

Assuming that x is an integer of 0 to N−3,Phase[x+2]−Phase[x+1]=Phase[x+1]−Phase[x] holds in all integers xsatisfying the assumption (however, even if <Condition #2> is notsatisfied, there is a possibility that the reception device obtains thehigh data reception quality).

In the case that symbol number i is an integer of 0 to G (G is aninteger of N−1 or more), all the N kinds of phase values of Phase[k] (kis an integer of 0 to N−1) are used in phase change value θ(i).

By way of example, phase change value θ(i)=Phase[ mod N] may be defined.mod is modulo, and therefore “i mod N” means a remainder when i isdivided by N.

The mapping performed to generate signals s1 and s2 in FIGS. 12 and 13will be described below.

(Modulation scheme used to generate signal s1(t), modulation scheme usedto generate signal s2(t))=(16 QAM, 16 QAM) will be described below.

“16 QAM mapping method #0”, “16 QAM mapping method #1”, “16 QAM mappingmethod #2”, and “16 QAM mapping method #3” are described above as the 16QAM mapping method.

At this point, in the transmission device, M kinds of 16 QAM signalpoint arrangement methods belonging to one of “16 QAM mapping method#0”, “16 QAM mapping method #1”, “16 QAM mapping method #2”, and “16 QAMmapping method #3” are prepared (M is an integer of 2 or more). At thispoint, mapper H1002 satisfies the following condition.

<Condition #3>

One of <3-1>, <3-2>, <3-3>, and <3-4> is satisfied.

<3-1>

In s1(i), all the M kinds of signal point arrangement methods areadopted.

<3-2>

In s2(i), all the M kinds of signal point arrangement methods areadopted.

<3-3>

All the M kinds of signal point arrangement methods are adopted ins1(i), and all the M kinds of signal point arrangement methods are alsoadopted in s2(i).

<3-4>

In the case that signal point arrangement method adopted in s1(i) andthe signal point arrangement method adopted in s2(i) are combined, thetransmission device adopts all the M kinds of signal point arrangementmethods.

The following condition holds by expressing the M kinds of 16 QAMmapping as “16 QAM signal point arrangement $k” (k is an integer of 0 toM−1).

<Condition #4>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $x”, and    (I_(y,j),Q_(y,j)) (j is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $y”. At    this point,-   {in the case that j is an integer of 0 to 15, i satisfying    I_(x,i)≠I_(y,i) exists in all integers j} or {in the case that j is    an integer of 0 to 15, i satisfying Q_(x,i)≠Q_(y,j) exists in all    integers j.}    }

In the reception device, a possibility of regularly generating a smallstate of the minimum Euclid of each of 256 reception candidate signalpoints (the candidate signal points of 16×16=256 exist because the 16QAM signal is simultaneously received through two lines) in the in-phaseI-orthogonal Q plane can be lowered by satisfying these conditions (forexample, in the case that the direct wave is dominant in the radio wavepropagation environment). Therefore, the reception device has a highpossibility of obtaining the high data reception quality.

The following matter holds for “g=h” in 16 QAM signal point arrangement$g and 16 QAM signal point arrangement $h.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g≠h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 16 QAM signal point arrangement $q₁,s2(t) 16 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 16 QAM signal point arrangement $q₁,s2(t) 16 QAM signalpoint arrangement $q₂), q₁ or p₂≠q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #5>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #6>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

An example of <Condition #6> will be described below. Phase[0] andPhase[1] exist because N=2 kinds of phase values exist as the phasechange value. L=3 kinds of mapping sets exist. Accordingly, “mapping set*0”, “mapping set *1”, and “mapping set *2” exist. At this point, FIG.17 illustrates the state in which <Condition #6> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, themapper H1002 in FIG. 12 or 13 performs the mapping using “mapping set*0”, and the phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer H1002 in FIG. 12 or13 uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapperH1002 in FIG. 12 or 13 performs the mapping using “mapping set *1”, andthe phase changer performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *1”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper H1002 in FIG. 12 or 13 performs the mappingusing “mapping set *2”, and the phase changer performs the phase changeusing Phase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #6>. Therefore, in the receptiondevice, a possibility of regularly generating a small state of theminimum Euclid of each of 256 reception candidate signal points (thecandidate signal points of 16×16=256 exist because the 16 QAM signal issimultaneously received through two lines) in the in-phase I-orthogonalQ plane can be lowered by satisfying these conditions (for example, inthe case that the direct wave is dominant in the radio wave propagationenvironment). Therefore, the reception device has a high possibility ofobtaining the high data reception quality.

The reception device has a possibility of obtaining the similaradvantage even if the following condition is satisfied instead of<Condition #6>.

<Condition #7>

In the case that x is an integer of 0 to L−1, x satisfying the followingmatter exists.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. All the N kinds of phase values of Phase[k] are used as phasechange value θ.}

(Modulation scheme used to generate signal s1(t), modulation scheme usedto generate signal s2(t))=(64 QAM,64 QAM) in the mapping of signals s1and s2 in FIGS. 12 and 13 will be described below.

“64 QAM mapping method #0”, “64 QAM mapping method #1”, “64 QAM mappingmethod #2”, and “64 QAM mapping method #3” are described above as the 64QAM mapping method.

At this point, in the transmission device, M kinds of 64 QAM signalpoint arrangement methods belonging to one of “64 QAM mapping method#0”, “64 QAM mapping method #1”, “64 QAM mapping method #2”, and “64 QAMmapping method #3” are prepared (M is an integer of 2 or more). At thispoint, the 64 QAM mapping method satisfies the following condition.

<Condition #8>

One of <8-1>, <8-2>, <8-3>, and <8-4> is satisfied.

<8-1>

In s1(i), all the M kinds of signal point arrangement methods areadopted.

<8-2>

In s2(i), all the M kinds of signal point arrangement methods areadopted.

<8-3>

All the M kinds of signal point arrangement methods are adopted ins1(i), and all the M kinds of signal point arrangement methods are alsoadopted in s2(i).

<8-4>

In the case that signal point arrangement method adopted in s1(i) andthe signal point arrangement method adopted in s2(i) are combined, allthe M kinds of signal point arrangement methods are adopted.

The following condition holds by expressing the M kinds of 64 QAMmapping as “64 QAM signal point arrangement $k” (k is an integer of 0 toM−1).

<Condition #9>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $x”, and    (I_(y,j),Q_(y,j)) (j is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $y”. At    this point,-   {in the case that j is an integer of 0 to 63, i satisfying    I_(x,i)≠I_(y,i) exists in all integers j} or {in the case that j is    an integer of 0 to 63, i satisfying Q_(x,i)≠Q_(y,j) exists in all    integers j.}    }

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 4096 receptioncandidate signal points (the candidate signal points of 64×64=4096 existbecause the 64 QAM signal is simultaneously received through two lines)in the in-phase I-orthogonal Q plane can be lowered by satisfying theseconditions (for example, in the case that the direct wave is dominant inthe radio wave propagation environment). Therefore, the reception devicehas a high possibility of obtaining the high data reception quality.

The following matter holds for “g=h” in 64 QAM signal point arrangement$g and 64 QAM signal point arrangement $h.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 63, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g≠h”, the following matter is satisfied.

{

(I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents coordinates ofeach of the 64 signal points in the in-phase I-orthogonal Q plane of “64QAM signal point arrangement $g”, and (I_(h,j),Q_(h,j)) (j is an integerof 0 to 63) represents coordinates of each of the 64 signal points inthe in-phase I-orthogonal Q plane of “64 QAM signal point arrangement$h”. At this point,

-   {in the case that that k is an integer of 0 to 63, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 64 QAM signal point arrangement $q₁,s2(t) 64 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 64 QAM signal point arrangement $q₁,s2(t) 64 QAM signalpoint arrangement $q₂), p₁≠q₁ or p₂≠q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #10>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #11>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using s1 and s2 generated using “mapping set *x”.At this point, all the N kinds of phase values of Phase[k] are used asphase change value θ.}

An example of <Condition #11> will be described below. Phase[0] andPhase[1] exist because N=2 kinds of phase values exist as the phasechange value. “Mapping set *0”, “mapping set *1”, and “mapping set *2”exist because L=3 kinds of mapping sets exist. At this point, FIG. 17illustrates the state in which <Condition #11> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, themapper in FIG. 12 or 13 performs the mapping using “mapping set *0”, andthe phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *1”, and the phasechanger performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *1”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *2”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #11>. In the reception device, apossibility of regularly generating a small state of the minimum Euclidof each of 4096 reception candidate signal points (the candidate signalpoints of 64×64=4096 exist because the 64 QAM signal is simultaneouslyreceived through two lines) in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

The reception device has a possibility of obtaining the similaradvantage even if the following condition is satisfied instead of<Condition #11>.

<Condition #12>

In the case that x is an integer of 0 to L−1, x satisfying the followingmatter exists.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using s1 and s2 generated using “mapping set *x”.At this point, all the N kinds of phase values of Phase[k] are used asphase change value θ.}

(s1(t) modulation scheme,s2(t) modulation scheme)=(256 QAM,256 QAM) inthe mapping of s1 and s2 in FIGS. 12 and 13 will be described below.

“256 QAM mapping method #0”, “256 QAM mapping method #1”, “256 QAMmapping method #2”, and “256 QAM mapping method #3” are described aboveas the 256 QAM mapping method.

At this point, M kinds of 256 QAM signal point arrangement methodsbelonging to one of “256 QAM mapping method #0”, “256 QAM mapping method#1”, “256 QAM mapping method #2”, and “256 QAM mapping method #3” areprepared (M is an integer of 2 or more) (in the transmission device). Atthis point, the 256 QAM mapping method satisfies the followingcondition.

<Condition #13>

One of <13-1>, <13-2>, <13-3>, and <13-4> is satisfied.

<13-1>

In s1(i), all the M kinds of signal point arrangement methods areadopted.

<13-2>

In s2(i), all the M kinds of signal point arrangement methods areadopted.

<13-3>

All the M kinds of signal point arrangement methods are adopted ins1(i), and all the M kinds of signal point arrangement methods are alsoadopted in s2(i).

<13-4>

In the case that signal point arrangement method adopted in s1(i) andthe signal point arrangement method adopted in s2(i) are combined, allthe M kinds of signal point arrangement methods are adopted.

The following condition holds by expressing the M kinds of 256 QAMmapping as “256 QAM signal point arrangement $k” (k is an integer of 0to M−1).

<Condition #14>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $x”, and    (I_(y,j),Q_(y,j)) (j is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $y”. At    this point,-   {in the case that j is an integer of 0 to 255, i satisfying    I_(x,i)≠I_(y,i) exists in all integers j} or-   {in the case that j is an integer of 0 to 255, i satisfying    Q_(x,i)≠Q_(y,j) exists in all integers j.}

}

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 65536reception candidate signal points (the candidate signal points of256×256=65536 exist because the 256 QAM signal is simultaneouslyreceived through two lines) in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

The following matter holds for “g=h” in 256 QAM signal point arrangement$g and 256 QAM signal point arrangement $h.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $h”.

At this point,

-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 256 QAM signal point arrangement $q₁,s2(t) 256 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 256 QAM signal point arrangement $q₁,s2(t) 256 QAM signalpoint arrangement $q₂), p₁≠q₁ or p₂≠q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #15>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #16>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

An example of <Condition #16> will be described below. Because N=2 kindsof phase values exist as the phase change value, Phase[0] and Phase[1]exist, and L=3 kinds of mapping sets exist. Accordingly, “mapping set*0”, “mapping set *1”, and “mapping set *2” exist. At this point, FIG.17 illustrates the state in which <Condition #16> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

At this point, attention is paid to “mapping set *0”. In time number 0,the mapper in FIG. 12 or 13 performs the mapping using “mapping set *0”,and the phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *1”, and the phasechanger performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *1”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *2”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #16>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 65536 reception candidate signal points(the candidate signal points of 256×256=65536 exist because the 256 QAMsignal is simultaneously received through two lines) in the in-phaseI-orthogonal Q plane can be lowered by satisfying these conditions (forexample, in the case that the direct wave is dominant in the radio wavepropagation environment). Therefore, the reception device has a highpossibility of obtaining the high data reception quality.

The reception device can obtain the similar advantage even if thefollowing condition is satisfied instead of <Condition #16>.

<Condition #17>

In the case that x is an integer of 0 to L−1, x satisfying the followingmatter exists.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

The transmission device that transmits the modulated signal, which isgenerated through the configuration in FIG. 14 using z1(t) and z2(t)generated in FIG. 12 or 13, is described above. Alternatively, thetransmission device may transmit the modulated signal that is generatedthrough the configuration in FIG. 14 using z1(t) and z2(t) generated inFIG. 18, 19, 20, or 21 instead of FIG. 12 or 13. Configurations in FIGS.18, 19, 20, and 21 will be described below.

First, the configuration in FIG. 18 will be described. In FIG. 18, thecomponent operated similarly to that in FIG. 12 is designated by thesame reference mark.

Referring to FIG. 18, data H1001 obtained by performing pieces ofprocessing such as error correction coding and interleaving (datarearrangement) and control signal H1012 are input to mapper H1002, andmapper H1002 sets a modulation scheme used to generate signal s1 and amodulation scheme used to generate signal s2 based on control signalH1012, performs the mapping in order to generate signals s1 and s2, andoutputs post-mapping signal s1(t) (H1003A) and post-mapping signal s2(t)(H1003B) (s1(t) and s2(t) are complex numbers). Signals s1 and s2 may bea function of frequency f or a function of time t and frequency f(accordingly, the output may be expressed as s1(f) and s2(f) or s1(t, f)and s2(t, f)). In this case, it is assumed that signals s1 and s2 arethe function of time t.

Post-mapping signal s2(t) (H1003B) and control signal H1012 are input tophase changer H1601, and phase changer H1601 sets regularly changingphase change value W) based on control signal H1012, performs the phasechange on post-mapping signal s2(t) (H1003B), and outputspost-phase-change signal H1602 (s2′(t)). Accordingly, post-phase-changesignal H1602 (s2′(t)) is given by the following equation.

[Mathematical formula 16]

s2′(t)=e ^(jλ(t)) ×s2(t)   (Equation 16)

j is an imaginary unit. Although phase change value θ(t) is dealt withas the function of time t, phase change value θ may be the function offrequency f or the function of frequency f and time t. The phase changeis described later.

Post-mapping signal s1(t) (H1003A) and control signal H1012 are input topower changer H1004A, and power changer H1004A sets coefficient u (u isa real number but not zero (u≠0)) based on control signal H1012,multiplies post-mapping signal s1(t) by coefficient u, and outputspost-power-change signal H1005A (x1(t)=u×s1(t)) (post-power-changesignal H1005A is set to x1(t)).

Post-phase-change signal H1602 (s2′(t)) and control signal H1012 areinput to power changer H1004B, and power changer H1004B sets coefficientv (v is a real number but not zero (v≠0)) based on control signal H1012,multiplies post-phase-change signal H1602 (s2′(t)) by coefficient v, andoutputs post-power-change signal H1005B (x2(t)=v×s2′(t))(post-power-change signal H1005B is set to x2(t)).

Power changer H1004A and power changer H1004B may output thepost-mapping signal of the input signal without changing power (at thispoint, u=1.0 and v=1.0 are obtained). Therefore, in the transmissiondevice of FIG. 18, power changer H1004A and power changer H1004B may beeliminated (the same holds true for FIGS. 19, 20, and 21).

Post-power-change signal H1005A (x1(t)), post-power-change signal H1005B(x2(t)), and control signal H1012 are input to weighting compositionpart H1006, and weighting composition part H1006 sets 2×2 matrix(pre-coding matrix) W including a complex number as an element based oncontrol signal H1012, multiplies matrix W by post-power-change signalH1005A (x1(t)) and post-power-change signal H1005B (x2(t)) (pre-coding),and outputs post-weighting-composition signal z1′(t) (H1007A) andpost-weighting-composition signal z2′(t) (H1007B).

Matrix (pre-coding matrix) W is given by the following equation.

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 17} \rbrack & \; \\{W = \begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 17} )\end{matrix}$

w11, w12, w21, and w22 may be or does not need to be a function of timet. w11, w12, w21, and w22 may be a real number or a complex number.

Post-weighting-composition signal z1′(t) (H1007A) andpost-weighting-composition signal z2′(t) (H1007B) are given by thefollowing equation.

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 18} \rbrack & \; \\{\begin{pmatrix}{z\; 1^{\prime}(t)} \\{z\; 2^{\prime}(t)}\end{pmatrix} = {\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}{x\; 1(t)} \\{x\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 18} )\end{matrix}$

Post-weighting-composition signal z2′(t) (H1007B) and control signalH1012 are input to phase changer H1008, and phase changer H1008 setsregularly changing phase change value θ(t) based on control signalH1012, performs a phase change on post-weighting-composition signalz2′(t) (H1007B), and outputs post-phase-change signal H1009 (z2″(t)).Accordingly, post-phase-change signal H1009 (z2″(t)) is given by thefollowing equation.

[Mathematical formula 19]

z2″(t)=e ^(jθ(t)) ×z2′(t)   (Equation 19)

j is an imaginary unit. Although phase change value θ(t) is dealt withas the function of time t, phase change value θ may be the function offrequency f or the function of frequency f and time t. The phase changeis described later.

Post-weighting-composition signal z1′(t) (H1007A) and control signalH1012 are input to power changer H1010A, and power changer H1010A setscoefficient a (a is a real number but not zero (a≠0)) based on controlsignal H1012, multiplies post-weighting-composition signal z1′(t)(H1007A) by coefficient a, and outputs post-power-change signal H1011A(z1(t)=a×z1′(t)) (post-power-change signal H1011A is set to z1(t)).

Post-phase-change signal H1009 (z2″(t)) and control signal H1012 areinput to power changer H1010B, and power changer H1010B sets coefficientb (b is a real number but not zero (b≠0)) based on control signal H1012,multiplies post-phase-change signal H1009 (z2″(t)) by coefficient b, andoutputs post-power-change signal H1011B (z2(t)=b×z2″(t))(post-power-change signal H1011B is set to z2(t)).

Power changer H1010A and power changer H1010B may output thepost-mapping signal of the input signal without changing power (at thispoint, a=1.0 and b=1.0 are obtained). In the transmission device of FIG.18, power changer H1010A and power changer H1010B may be eliminated (thesame holds true for FIGS. 19, 20, and 21).

Therefore, a relationship between s1(t) and s2(t) and z1(t) and z2(t)are given as follows.

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 20} \rbrack} & \; \\{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\lambda {(t)}}}\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 20} )\end{matrix}$

(Equation 20) is equivalent to (Equation 21).

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 21} \rbrack} & \; \\{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\lambda {(t)}}}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 21} )\end{matrix}$

In order to obtain (Equation 21), a configuration in which positions ofphase changer H1601 and power changer H1004B in FIG. 18 are replacedwith each other is illustrated in FIG. 19. The detailed description ofthe transmission device in FIG. 19 is omitted because the transmissiondevice in FIG. 19 performs (Equation 21) similarly to the transmissiondevice in FIG. 18. In the operation of FIG. 19, “phase changer H1701performs the phase change on the input signal and outputs thepost-phase-change signal” and “power changer H1004B performs the powerchange on the input signal and outputs the post-power-change signal”.

(Equation 20) and (Equation 21) are equivalent to (Equation 22).

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 22} \rbrack} & \; \\{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\lambda {(t)}}}\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 22} )\end{matrix}$

In order to obtain (Equation 22), a configuration in which positions ofphase changer H1008 and power changer H1010B in FIG. 18 are replacedwith each other is illustrated in FIG. 20. The detailed description ofthe transmission device in FIG. 20 is omitted because the transmissiondevice in FIG. 20 performs (Equation 22) similarly to the transmissiondevice in FIG. 18. In FIG. 20, “phase changer H1801 performs the phasechange on the input signal and outputs the post-phase-change signal” and“power changer H1010B performs the power change on the input signal andoutputs the post-power-change signal”.

(Equation 20), (Equation 21), and (Equation 22) are equivalent to(Equation 23).

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 23} \rbrack} & \; \\{\begin{pmatrix}{z\; 1(t)} \\{z\; 2(t)}\end{pmatrix} = {\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\lambda {(t)}}}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 23} )\end{matrix}$

In order to obtain (Equation 23), a configuration in which positions ofphase changer H1008 and power changer H1010B in FIG. 19 are replacedwith each other is illustrated in FIG. 21. The detailed description ofthe transmission device in FIG. 21 is omitted because the transmissiondevice in FIG. 21 performs (Equation 23) similarly to the transmissiondevice in FIG. 18. In FIG. 21, “phase changer H1901 performs the phasechange on the input signal and outputs the post-phase-change signal” and“power changer H1010B performs the power change on the input signal andoutputs the post-power-change signal”.

z1(t) and z2(t) are transmitted from different antennas at the sameclock time and the same frequency (common frequency).

Although z1(t) and z2(t) are the functions of time t, z1(t) and z2(t)may be the function of frequency f or the function of time t andfrequency f (accordingly, the output may be expressed as z1(f) and z2(f)or z1(t, f) and z2(t, f)). In this case, z1(t) and z2(t) are describedas the function of time t.

Therefore, z1(t), z2(t), z1′(t), z2′(t), and z2″(t) are also thefunction of time. However, z1(t), z2(t), z1′(t), z2′(t), and z2″(t) maybe the function of frequency f or the function of time t and frequencyf.

In FIGS. 14 and 15, the detailed description is omitted because of thesimilar operation.

FIG. 16 illustrates a relationship between the transmission device andthe reception device in FIGS. 18, 19, 20, and 21. The operation of thetransmission device is described above. The operation of the receptiondevice will be described below.

FIG. 16 illustrates transmission device H1401 and reception deviceH1402. In the case that r1 is a reception signal of antenna RX1 of thereception device H1402, that r2 is a reception signal of antenna RX2,and that h11, h12, h21, and h22 are a factor of radio wave propagation(channel fluctuation) between the antennas of the transmitter andreceiver, the following equation holds.

$\begin{matrix}{\mspace{79mu} \lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 24} \rbrack} & \; \\{\begin{pmatrix}{{r1}(t)} \\{r\; 2(t)}\end{pmatrix} = {{\begin{pmatrix}{h_{11}(t)} & {h_{12}(t)} \\{h_{21}(t)} & {h_{22}(t)}\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\theta {(t)}}}\end{pmatrix}\begin{pmatrix}a & 0 \\0 & b\end{pmatrix}\begin{pmatrix}w_{11} & w_{12} \\w_{21} & w_{22}\end{pmatrix}\begin{pmatrix}1 & 0 \\0 & e^{j\; {\lambda {(t)}}}\end{pmatrix}\begin{pmatrix}u & 0 \\0 & v\end{pmatrix}\begin{pmatrix}{s\; 1(t)} \\{s\; 2(t)}\end{pmatrix}} + \begin{pmatrix}{n\; 1(t)} \\{n\; 2(t)}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 24} )\end{matrix}$

In the above equation, n1 and n2 are noises.

In (Equation 24), each variable is the function of time t.Alternatively, each variable may be the function of frequency f or thefunction of time t and frequency f (in this case, each variable is thefunction of time t).

Channel estimator H1403A in FIG. 16 estimates values of h11(t) andh12(t) in (Equation 24) using, for example, the pilot symbol in FIG. 15.Channel estimator H1403B in FIG. 16 estimates values of h21(t) andh22(t) in (Equation 24) using, for example, the pilot symbol in FIG. 15.

Signal processor H1404 in FIG. 16 obtains a logarithmic likelihood ratioof each bit of the data transmitted by the transmission device using therelationship of (Equation 24). Then, signal processor H1404 performspieces of processing such as deinterleaving and error correctiondecoding to obtain reception information (see NPLs 5 and 6).

A way to switch the mapping method, pre-coding matrix, and phase changeof signals s1 and s2 in FIGS. 18, 19, 20, and 21 will be describedbelow.

First, a way to provide phase change value θ(t) in (Equation 19) will bedescribed. In symbol number i (i is an integer of 0 or more), a valuethat can be taken by phase change value θ(i) is N kinds (N is an integerof 2 or more) of phase values. The N kinds of phase values are expressedby Phase[k] (k is an integer of 0 to N−1 and 0 radian <Phase[k]<2πradian). All the N kinds of phase values of Phase[k] are used in phasechange value θ(i). <Condition #1> holds, which allows the receptiondevice to obtain the high data reception quality.

Additionally, <Condition #2> may be satisfied (however, even if<Condition #2> is not satisfied, there is a possibility that thereception device obtains the high data reception quality).

In the case that i is an integer of 0 to G (G is an integer of N−1 ormore), all the N kinds of phase values of Phase[k] (k is an integer of 0to N−1) are used in phase change value θ(i).

By way of example, phase change value θ(i)=Phase[i mod N] may bedefined. mod is modulo, and therefore “i mod N” means a remainder when iis divided by N.

The mapping performed to generate signals s1 and s2 in FIGS. 18, 19, 20,and 21 will be described below.

(Modulation scheme used to generate signal s1(t), modulation scheme usedto generate signal s2(t))=(16 QAM,16 QAM) will be described below.

“16 QAM mapping method #0”, “16 QAM mapping method #1”, “16 QAM mappingmethod #2”, and “16 QAM mapping method #3” are described above as the 16QAM mapping method.

At this point, in the transmission device, M kinds of 16 QAM signalpoint arrangement methods belonging to one of “16 QAM mapping method#0”, “16 QAM mapping method #1”, “16 QAM mapping method #2”, and “16 QAMmapping method #3” are prepared (M is an integer of 2 or more). At thispoint, mapper H1002 satisfies <Condition #3>.

<Condition #4> holds by expressing the M kinds of 16 QAM mapping as “16QAM signal point arrangement $k” (k is an integer of 0 to M−1).

In the reception device, a possibility of regularly generating a smallstate of the minimum Euclid of each of 256 reception candidate signalpoints (the candidate signal points of 16×16=256 exist because the 16QAM signal is simultaneously received through two lines) in the in-phaseI-orthogonal Q plane can be lowered by satisfying these conditions (forexample, in the case that the direct wave is dominant in the radio wavepropagation environment). Therefore, the reception device has a highpossibility of obtaining the high data reception quality.

The following matter holds for “g=h” in 16 QAM signal point arrangement$g and 16 QAM signal point arrangement $h.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g≠h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “16 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}

}

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 16 QAM signal point arrangement $q₁,s2(t) 16 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 16 QAM signal point arrangement$p₁,s2(t) 16 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 16 QAM signal point arrangement $q₁,s2(t) 16 QAM signalpoint arrangement $q₂), q₁ or p₂=q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 18, 19, 20,and 21) prepares L (L is an integer of 2 or more) kinds of mapping sets,and sets the L kinds of mapping sets to “mapping set *k” (k is aninteger of 0 to L−1). At this point, the L kinds of mapping sets satisfy<Condition #5>.

<Condition #6> is provided. An example of <Condition #6> will bedescribed below. Phase[0] and Phase[1] exist because N=2 kinds of phasevalues exist as the phase change value. L=3 kinds of mapping sets exist.Accordingly, “mapping set *0”, “mapping set *1”, and “mapping set *2”exist. At this point, FIG. 17 illustrates the state in which <Condition#6> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

At this point, attention is paid to “mapping set *0”. In time number 0,mapper H1002 in FIG. 18, 19, 20, or 21 performs the mapping using“mapping set *0”, and phase changer H1008, H1801, or H1901 performs thephase change using Phase[0].

In time number 1, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *0”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *0”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *1”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 3, the mapper in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *1”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *1”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *2”. In time number 4, mapper H1002 inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *2”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 5, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *2”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *2”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Therefore, FIG. 17 satisfies <Condition #6>. In the reception device, apossibility of regularly generating a small state of the minimum Euclidof each of 256 reception candidate signal points (the candidate signalpoints of 16×16=256 exist because the 16 QAM signal is simultaneouslyreceived through two lines) in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

There is a possibility of being able to obtain the similar advantageeven if <Condition #7> is satisfied instead of <Condition #6>.

(Modulation scheme used to generate signal s1(t), modulation scheme usedto generate signal s2(t))=(64 QAM,64 QAM) in the mapping of signals s1and s2 in FIG. 18, 19, 20, or 21 will be described below.

“64 QAM mapping method #0”, “64 QAM mapping method #1”, “64 QAM mappingmethod #2”, and “64 QAM mapping method #3” are described above as the 64QAM mapping method.

At this point, in the transmission device, M kinds of 64 QAM signalpoint arrangement methods belonging to one of “64 QAM mapping method#0”, “64 QAM mapping method #1”, “64 QAM mapping method #2”, and “64 QAMmapping method #3” are prepared (M is an integer of 2 or more). At thispoint, <Condition #8> is satisfied.

<Condition #9> holds by expressing the M kinds of 64 QAM mapping as “64QAM signal point arrangement $k” (k is an integer of 0 to M−1).

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 4096 receptioncandidate signal points (the candidate signal points of 64×64=4096 existbecause the 64 QAM signal is simultaneously received through two lines)in the in-phase I-orthogonal Q plane can be lowered by satisfying theseconditions (for example, in the case that the direct wave is dominant inthe radio wave propagation environment). Therefore, the reception devicehas a high possibility of obtaining the high data reception quality.

The following matter holds for “g=h” in 64 QAM signal point arrangement$g and 64 QAM signal point arrangement $h.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $h”. At    this point,

{in the case that that k is an integer of 0 to 63, the case thatI_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}

}

Similarly, for “g≠h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “64 QAM signal point arrangement $h”. At    this point,

{in the case that that k is an integer of 0 to 63, the case thatI_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers k.}

}

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 64 QAM signal point arrangement $q₁,s2(t) 64 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 64 QAM signal point arrangement$p₁,s2(t) 64 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 64 QAM signal point arrangement $q₁,s2(t) 64 QAM signalpoint arrangement $q₂), p₁≠q₁ or p₂≠q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 18, 19, 20,and 21) prepares L (L is an integer of 2 or more) kinds of mapping sets,and sets the L kinds of mapping sets to “mapping set *k” (k is aninteger of 0 to L−1). At this point, the L kinds of mapping sets satisfy<Condition #10>.

<Condition #11> is provided. An example of <Condition #11> will bedescribed below. Phase[0] and Phase[1] exist because N=2 kinds of phasevalues exist as the phase change value. L=3 kinds of mapping sets exist.Accordingly, “mapping set *0”, “mapping set *1”, and “mapping set *2”exist. At this point, FIG. 17 illustrates the state in which <Condition#11> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, mapperH1002 in FIG. 18, 19, 20, or 21 performs the mapping using “mapping set*0”, and phase changer H1008, H1801, or H1901 performs the phase changeusing Phase[0].

In time number 1, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *0”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *0”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *1”. In time number 2, mapper H1002 inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *1”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 3, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *1”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *1”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *2”. In time number 4, mapper H1002 inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *2”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 5, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *2”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *2”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Therefore, FIG. 17 satisfies <Condition #11>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 4096 reception candidate signal points(the candidate signal points of 64×64=4096 exist because the 64 QAMsignal is simultaneously received through two lines) in the in-phaseI-orthogonal Q plane can be lowered by satisfying these conditions (forexample, in the case that the direct wave is dominant in the radio wavepropagation environment). Therefore, the reception device has a highpossibility of obtaining the high data reception quality.

There is a possibility of being able to obtain the similar advantageeven if <Condition #12> is satisfied instead of <Condition #11>.

(Modulation scheme used to generate signal s1(t), modulation scheme usedto generate signal s2(t))=(256 QAM,256 QAM) in the mapping of signals s1and s2 in FIG. 18, 19, 20, or 21 will be described below.

“256 QAM mapping method #0”, “256 QAM mapping method #1”, “256 QAMmapping method #2”, and “256 QAM mapping method #3” are described aboveas the 256 QAM mapping method.

At this point, in the transmission device, M kinds of 256 QAM signalpoint arrangement methods belonging to one of “256 QAM mapping method#0”, “256 QAM mapping method #1”, “256 QAM mapping method #2”, and “256QAM mapping method #3” are prepared (M is an integer of 2 or more). Atthis point, the 256 QAM mapping method satisfies <Condition #13>.

<Condition #14> holds by expressing the M kinds of 256 QAM mapping as“256 QAM signal point arrangement $k” (k is an integer of 0 to M−1).

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 65536reception candidate signal points (the candidate signal points of256×256=65536 exist because the 256 QAM signal is simultaneouslyreceived through two lines) in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

The following matter holds for “g=h” in 256 QAM signal point arrangement$g and 256 QAM signal point arrangement $h.

{

-   (i_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $g”, and    (I_(h,j),Q_(h,j)) (j is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “256 QAM signal point arrangement $h”. At    this point,-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 256 QAM signal point arrangement $q₁,s2(t) 256 QAM signalpoint arrangement $q₂), p₁=q₁ and p₂=q₂ hold in the case that the firstmapping set is identical to the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (s1(t) 256 QAM signal point arrangement$p₁,s2(t) 256 QAM signal point arrangement $p₂) while the second mappingset is (s1(t) 256 QAM signal point arrangement $q₁,s2(t) 256 QAM signalpoint arrangement $q₂), p₁≠q₁ or p₂≠q₂ holds in the case that the firstmapping set is different from the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 18, 19, 20,and 21) prepares L (L is an integer of 2 or more) kinds of mapping sets,and sets the L kinds of mapping sets to “mapping set *k” (k is aninteger of 0 to L−1). At this point, the L kinds of mapping sets satisfy<Condition #15>.

<Condition #16> is provided. An example of <Condition #16> will bedescribed below. Phase[0] and Phase[1] exist because N=2 kinds of phasevalues exist as the phase change value. L=3 kinds of mapping sets exist.Accordingly, “mapping set *0”, “mapping set *1”, and “mapping set *2”exist. At this point, FIG. 17 illustrates the state in which <Condition#16> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, mapperH1002 in FIG. 18, 19, 20, or 21 performs the mapping using “mapping set*0”, and phase changer H1008, H1801, or H1901 performs the phase changeusing Phase[0].

In time number 1, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *0”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *0”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *1”. In time number 2, mapper H1002 inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *1”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 3, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *1”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *1”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Attention is paid to “mapping set *2”. In time number 4, mapper H1002 inFIG. 18, 19, 20, or 21 performs the mapping using “mapping set *2”, andphase changer H1008, H1801, or H1901 performs the phase change usingPhase[0].

In time number 5, mapper H1002 in FIG. 18, 19, 20, or 21 performs themapping using “mapping set *2”, and phase changer H1008, H1801, or H1901performs the phase change using Phase[1].

Accordingly, for “mapping set *2”, the phase changer H1008, H1801, orH1901 in FIG. 18, 19, 20, or 21 uses all the N=2 kinds of phase valuesof Phase[k].

Therefore, FIG. 17 satisfies <Condition #16>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 65536 reception candidate signal points(the candidate signal points of 256×256=65536 exist because the 256 QAMsignal is simultaneously received through two lines) in the in-phaseI-orthogonal Q plane can be lowered by satisfying these conditions (forexample, in the case that the direct wave is dominant in the radio wavepropagation environment). Therefore, the reception device has a highpossibility of obtaining the high data reception quality.

There is a possibility of being able to obtain the similar advantageeven if <Condition #17> is satisfied instead of <Condition #16>.

Phase change value λ(t) (see Equation 16) used by phase changers H1601and H1701 in FIGS. 18, 19, 20, and 21 may regularly be changed similarlyto, for example, phase change value e(t). Although λ(t) is dealt with asthe function of time t (or “the function of frequency f” or “thefunction of time t and frequency f”), λ may be a fixed value.

Pre-coding matrix W of (Equation 10) and (Equation 17) in the exemplaryembodiment may be a fixed pre-coding matrix, or may be changed by time t(or “frequency f” or “time t and frequency f”). An example of pre-codingmatrix W will be described below.

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 25} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times e^{j\; 0}} & {\beta \times \alpha \times e^{j\; 0}} \\{\beta \times \alpha \times e^{j\; 0}} & {\beta \times e^{j\; \pi}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 25} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 26} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j\; 0} & {\alpha \times e^{j\; 0}} \\{\alpha \times e^{j\; 0}} & e^{j\; \pi}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 26} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 27} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times e^{j\; 0}} & {\beta \times \alpha \times e^{j\; \pi}} \\{\beta \times \alpha \times e^{j\; 0}} & {\beta \times e^{j\; 0}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 27} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 28} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{j\; 0} & {\alpha \times e^{j\; \pi}} \\{\alpha \times e^{j\; 0}} & e^{j\; 0}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 28} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 29} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \alpha \times e^{j\; 0}} & {\beta \times e^{j\; \pi}} \\{\beta \times e^{j\; 0}} & {\beta \times \alpha \times e^{j\; 0}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 29} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 30} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j\; 0}} & e^{j\; \pi} \\e^{j\; 0} & {\alpha \times e^{j\; 0}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 30} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 31} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \alpha \times e^{j\; 0}} & {\beta \times e^{j\; 0}} \\{\beta \times e^{j\; 0}} & {\beta \times \alpha \times e^{j\; \pi}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 31} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 32} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j\; 0}} & e^{j\; 0} \\e^{j\; 0} & {\alpha \times e^{j\; \pi}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 32} )\end{matrix}$

In (Equation 25), (Equation 26), (Equation 27), (Equation 28), (Equation29), (Equation 30), (Equation 31), and (Equation 32), variable α may bea real number or an imaginary number, and variable β may be a realnumber or an imaginary number. Note that variable α is not 0 (zero) andvariable β is not 0 (zero).

or

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 33} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \cos \mspace{14mu} x} & {\beta \times \sin \mspace{14mu} x} \\{\beta \times \sin \mspace{14mu} x} & {{- \beta} \times \cos \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 33} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 34} \rbrack & \; \\{W = \begin{pmatrix}{\cos \mspace{14mu} x} & {\sin \mspace{14mu} x} \\{\sin \mspace{14mu} x} & {{- \cos}\mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 34} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 35} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \cos \mspace{14mu} x} & {{- \beta} \times \sin \mspace{14mu} x} \\{\beta \times \sin \mspace{14mu} x} & {\beta \times \cos \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 35} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 36} \rbrack & \; \\{W = \begin{pmatrix}{\cos \mspace{14mu} x} & {{- \sin}\mspace{14mu} x} \\{\sin \mspace{14mu} x} & {\cos \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 36} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 37} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \sin \mspace{14mu} x} & {{- \beta} \times \cos \mspace{14mu} x} \\{\beta \times \cos \mspace{14mu} x} & {\beta \times \sin \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 37} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 38} \rbrack & \; \\{W = \begin{pmatrix}{\sin \mspace{14mu} x} & {{- \cos}\mspace{14mu} x} \\{\cos \mspace{14mu} x} & {\sin \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 38} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 39} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \sin \mspace{14mu} x} & {\beta \times \cos \mspace{14mu} x} \\{\beta \times \cos \mspace{14mu} x} & {{- \beta} \times \sin \mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 39} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 40} \rbrack & \; \\{W = \begin{pmatrix}{\sin \mspace{14mu} x} & {\cos \mspace{14mu} x} \\{\cos \mspace{14mu} x} & {{- \sin}\mspace{14mu} x}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 40} )\end{matrix}$

In (Equation 33), (Equation 34), (Equation 35), (Equation 36), (Equation37), (Equation 38), (Equation 39), and (Equation 40), angle x is a realnumber (unit is “radian” or “degree”). In (Equation 33), (Equation 35),(Equation 37), and (Equation 39), variable β may be a real number or animaginary number. Note that variable β is not 0 (zero).

or

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 41} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times e^{{jX}_{11}}} & {\beta \times \alpha \times e^{j{({X_{11} + Y})}}} \\{\beta \times \alpha \times e^{{jX}_{21}}} & {\beta \times e^{j{({X_{21} + Y + \pi})}}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 41} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 42} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{{jX}_{11}} & {\alpha \times e^{j{({X_{11} + Y})}}} \\{\alpha \times e^{{jX}_{21}}} & e^{j{({X_{21} + Y + \pi})}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 42} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 43} \rbrack & \; \\{W = \begin{pmatrix}{\beta \times \alpha \times e^{{jX}_{21}}} & {\beta \times e^{j{({X_{21} + Y + \pi})}}} \\{\beta \times e^{{jX}_{11}}} & {\beta \times \alpha \times e^{j{({X_{11} + Y})}}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 43} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 44} \rbrack & \; \\{W = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{{jX}_{21}}} & e^{j{({X_{21} + Y + \pi})}} \\e^{{jX}_{11}} & {\alpha \times e^{j{({X_{11} + Y})}}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 44} )\end{matrix}$

In (Equation 41), (Equation 42), (Equation 43), and (Equation 44),angles X₁₁ and X₂₁ are a real number (unit is “radian” or “degree”)(fixed value), angle Y is a fixed value (real number), and variable αmay be a real number or an imaginary number. In (Equation 41) and(Equation 43), variable β may be a real number or an imaginary number.Note that variable α is not 0 (zero) and variable β is not 0 (zero).

or

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 45} \rbrack & \; \\{{W(i)} = \begin{pmatrix}{\beta \times e^{{jX}_{11}{(i)}}} & {\beta \times \alpha \times e^{j{({{X_{11}{(i)}} + \lambda})}}} \\{\beta \times \alpha \times e^{{jX}_{21}{(i)}}} & {\beta \times e^{j{({{X_{21}{(i)}} + \lambda + \pi})}}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 45} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 46} \rbrack & \; \\{{W(i)} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}e^{{jX}_{11}{(i)}} & {\alpha \times e^{j{({{X_{11}{(i)}} + Y})}}} \\{\alpha \times e^{{jX}_{21}{(i)}}} & e^{j{({{X_{21}{(i)}}\mspace{11mu} {Y}\pi})}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 46} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 47} \rbrack & \; \\{{W(i)} = \begin{pmatrix}{\beta \times \alpha \times e^{{jX}_{21}{(i)}}} & {\beta \times e^{j{({{X_{21}{(i)}} + Y + \pi})}}} \\{\beta \times e^{{jX}_{11}{(i)}}} & {\beta \times \alpha \times e^{j{({{X_{11}{(i)}} + Y})}}}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 47} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 48} \rbrack & \; \\{{W(i)} = {\frac{1}{\sqrt{\alpha^{2} + 1}}\begin{pmatrix}{\alpha \times e^{j\; {\theta_{21}{(i)}}}} & e^{j{({{\theta_{21}{(i)}} + Y + \pi})}} \\e^{j\; {\theta_{11}{(i)}}} & {\alpha \times e^{j{({{\theta_{11}{(i)}} + Y})}}}\end{pmatrix}}} & ( {{Equation}\mspace{14mu} 48} )\end{matrix}$

In (Equation 45), (Equation 46), (Equation 47), and (Equation 48),angles X₁₁(i) and X₂₁(i) are a real number (unit is “radian” or“degree”), angles X₁₁(i) and X₂₁(i) are the function of variable i(“time”, “frequency”, or “time and frequency”), angle Y is a fixed value(real number), and variable α may be a real number or an imaginarynumber. In (Equation 45) and (Equation 47), variable β may be a realnumber or an imaginary number. Note that variable α is not 0 (zero) andvariable β is not 0 (zero).

or

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 49} \rbrack & \; \\{W = \begin{pmatrix}p & 0 \\0 & q\end{pmatrix}} & ( {{Equation}\mspace{14mu} 49} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 50} \rbrack & \; \\{W = \begin{pmatrix}0 & p \\q & 0\end{pmatrix}} & ( {{Equation}\mspace{14mu} 50} )\end{matrix}$

In (Equation 49) and (Equation 50), variables p and q may be a realnumber (fixed value) or an imaginary number (fixed value). Note thatvariable p is not 0 (zero) and variable q is not 0 (zero).

or

$\begin{matrix}\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 51} \rbrack & \; \\{{W(i)} = \begin{pmatrix}{p(i)} & 0 \\0 & {q(i)}\end{pmatrix}} & ( {{Equation}\mspace{14mu} 51} ) \\{or} & \; \\\lbrack {{Mathematical}\mspace{14mu} {formula}\mspace{14mu} 52} \rbrack & \; \\{{W(i)} = \begin{pmatrix}0 & {p(i)} \\{q(i)} & 0\end{pmatrix}} & ( {{Equation}\mspace{14mu} 52} )\end{matrix}$

In (Equation 51) and (Equation 52), functions p(i) and q(i) may be areal number or an imaginary number, and is the function of variable i(“time”, “frequency”, or “time and frequency”). Note that function p(i)is not 0 (zero) and function q(i) is not 0 (zero).

The exemplary embodiment can also be performed even if a pre-codingmatrix except for the above pre-coding matrix is used. At this point,pre-coding matrix W is a full rank.

The exemplary embodiment can be performed in the case that the followingcondition is satisfied for the mapping.

(Modulation scheme used to generate s1(t), modulation scheme used togenerate s2(t))=(modulation scheme involving 16 signal points in I-Qplane (4-bit transmission per symbol), modulation scheme involving 16signal points in I-Q plane (4-bit transmission per symbol)) in themapping of 51 and mapping of s2 in FIGS. 12 and 13 will be describedbelow.

M (M is an integer of 2 or more) kinds of methods for arranging thesignal point of the modulation scheme involving the 16 signal points inthe I-Q plane (4-bit transmission per symbol) are prepared in thetransmission device. At this point, the following condition is satisfiedin the transmission device.

<Condition #18>

One of <18-1>, <18-2>, <18-3>, and <18-4> is satisfied.

<18-1>

In s1(i), all the M kinds of mapping methods are adopted.

<18-2>

In s2(i), all the M kinds of mapping methods are adopted.

<18-3>

All the M kinds of mapping methods are adopted in s1 (i), and all the Mkinds of mapping methods are also adopted in s2(i).

<18-4>

In the case that the mapping method adopted in s1(i) and the mappingmethod adopted in s2(i) are combined, all the M kinds of mapping methodsare adopted.

The M kinds of mapping methods for the modulation scheme involving the16 signal points in the I-Q plane (4-bit transmission per symbol) areexpressed as “signal point arrangement $k of modulation scheme involving16 signal points” (k is an integer of 0 to M−1), whereby the followingcondition holds.

<Condition #19>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $x of modulation    scheme involving 16 signal points”, and that (I_(y,j),Q_(y,j)) (j is    an integer of 0 to 15) represents coordinates of each of the 16    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $y of modulation scheme involving 16 signal points”. At    this point,-   {in the case that j is an integer of 0 to 15, i satisfying    I_(x,i)≠I_(y,i) exists in all integers j} or {in the case that j is    an integer of 0 to 15, i satisfying Q_(x,i)≠Q_(y,j) exists in all    integers j.}    }

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 256 receptioncandidate signal points in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

The following matter holds in the case that “g=h” holds in signal pointarrangement $g of the modulation scheme involving the 16 signal pointsand signal point arrangement $h of the modulation scheme involving the16 signal points.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $g of modulation    scheme involving 16 signal points”, and that (I_(h,j),Q_(h,j)) (j is    an integer of 0 to 15) represents coordinates of each of the 16    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $h of modulation scheme involving 16 signal points”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 15) represents    coordinates of each of the 16 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $g of modulation    scheme involving 16 signal points”, and that (I_(h,j),Q_(h,j)) (j is    an integer of 0 to 15) represents coordinates of each of the 16    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $h of modulation scheme involving 16 signal points”. At    this point,-   {in the case that that k is an integer of 0 to 15, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(signal point arrangement $p₁ ofmodulation scheme involving 16 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 16 s2(t) signal points)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 16 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 16 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 16 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 16 s2(t) signal points),p₁=q₁ and p₂=q₂ hold in the case that the first mapping set is identicalto the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 16 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 16 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 16 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 16 s2(t) signal points),p₁≠q₁ and p₂≠q₂ hold in the case that the first mapping set is differentfrom the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #20>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #21>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

An example of <Condition #21> will be described below. Phase[0] andPhase[1] exist because N=2 kinds of phase values exist as the phasechange value. “Mapping set *0”, “mapping set *1”, and “mapping set *2”exist because L=3 kinds of mapping sets exist. FIG. 17 illustrates thestate in which <Condition #21> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, themapper in FIG. 12 or 13 performs the mapping using “mapping set *0”, andthe phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *1”, and the phasechanger performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *2”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #21>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 256 reception candidate signal points inthe in-phase I-orthogonal Q plane can be lowered by satisfying theseconditions (for example, in the case that the direct wave is dominant inthe radio wave propagation environment). Therefore, the reception devicehas a high possibility of obtaining the high data reception quality.

The reception device can obtain the similar advantage even if thefollowing condition is satisfied instead of <Condition #21>.

<Condition #22>

In the case that x is an integer of 0 to L−1, x satisfying the followingmatter exists.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

(Modulation scheme used to generate s1(t), modulation scheme used togenerate s2(t))=(modulation scheme involving 64 signal points in I-Qplane (6-bit transmission per symbol), modulation scheme involving 64signal points in I-Q plane (6-bit transmission per symbol)) in themapping performed to generate s1 and s2 in FIGS. 12 and 13 will bedescribed below.

M (M is an integer of 2 or more) kinds of methods for arranging thesignal point of the modulation scheme involving the 64 signal points inthe I-Q plane (6-bit transmission per symbol) are prepared in thetransmission device. At this point, the following condition is satisfiedin the transmission device.

<Condition #23>

One of <23-1>, <23-2>, <23-3>, and <23-4> is satisfied.

<23-1>

In s1(i), all the M kinds of signal point arrangement methods areadopted.

<23-2>

In s2(i), all the M kinds of signal point arrangement methods areadopted.

<23-3>

All the M kinds of signal point arrangement methods are adopted ins1(i), and all the M kinds of signal point arrangement methods are alsoadopted in s2(i).

<23-4>

In the case that signal point arrangement method adopted in s1(i) andthe signal point arrangement method adopted in s2(i) are combined, allthe M kinds of signal point arrangement methods are adopted.

The M kinds of mapping methods for the modulation scheme involving the64 signal points in the I-Q plane (6-bit transmission per symbol) areexpressed as “signal point arrangement $k of modulation scheme involving64 signal points” (k is an integer of 0 to M−1), whereby the followingcondition holds.

<Condition #24>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $x of modulation    scheme involving 64 signal points”, and that (I_(y,j),Q_(y,j)) (j is    an integer of 0 to 63) represents coordinates of each of the 64    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $y of modulation scheme involving 64 signal points”. At    this point,-   {in the case that j is an integer of 0 to 63, i satisfying    I_(x,i)≠I_(y,i) exists in all integers j} or {in the case that j is    an integer of 0 to 63, i satisfying Q_(x,i)≠Q_(y,j) exists in all    integers j.}    }

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 4096 receptioncandidate signal points in the in-phase I-orthogonal Q plane can belowered by satisfying these conditions (for example, in the case thatthe direct wave is dominant in the radio wave propagation environment).Therefore, the reception device has a high possibility of obtaining thehigh data reception quality.

The following matter holds in the case that “g=h” holds in signal pointarrangement $g of the modulation scheme involving the 64 signal pointsand signal point arrangement $h of the modulation scheme involving the64 signal points.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $g of modulation    scheme involving 64 signal points”, and that (I_(h,j),Q_(h,j)) (j is    an integer of 0 to 63) represents coordinates of each of the 64    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $h of modulation scheme involving 64 signal points”. At    this point,-   {in the case that that k is an integer of 0 to 63, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g h”, the following matter is satisfied.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 63) represents    coordinates of each of the 64 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $g of modulation    scheme involving 64 signal points”, and that (I_(h,j),Q_(h,j)) (j is    an integer of 0 to 63) represents coordinates of each of the 64    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $h of modulation scheme involving 64 signal points”. At    this point,-   {in the case that that k is an integer of 0 to 63, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(signal point arrangement $p₁ ofmodulation scheme involving 64 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 64 s2(t) signal points)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 64 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 64 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 64 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 64 s2(t) signal points),p₁=q₁ and p₂=q₂ hold in the case that the first mapping set is identicalto the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 64 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 64 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 64 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 64 s2(t) signal points),p₁≠q₁ and p₂≠q₂ hold in the case that the first mapping set is differentfrom the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #25>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #26>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

An example of <Condition #26> will be described below. Phase[0] andPhase[1] exist because N=2 kinds of phase values exist as the phasechange value. “Mapping set *0”, “mapping set *1”, and “mapping set *2”exist because L=3 kinds of mapping sets exist. FIG. 17 illustrates thestate in which <Condition #26> is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, themapper in FIG. 12 or 13 performs the mapping using “mapping set *0”, andthe phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *1”, and the phasechanger performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *1”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *2”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #26>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 4096 reception candidate signal points inthe in-phase I-orthogonal Q plane can be lowered by satisfying theseconditions (for example, in the case that the direct wave is dominant inthe radio wave propagation environment). Therefore, the reception devicehas a high possibility of obtaining the high data reception quality.

The reception device can obtain the similar advantage even if thefollowing condition is satisfied instead of <Condition #26>.

<Condition #27>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

(Modulation scheme involving 256 signal points in I-Q plane (8-bittransmission per symbol), modulation scheme involving 256 signal pointsin I-Q plane (8-bit transmission per symbol)) in the mapping performedto generate s1 and s2 in FIGS. 12 and 13 will be described below.

M (M is an integer of 2 or more) kinds of methods for arranging thesignal point of the modulation scheme involving the 256 signal points inthe I-Q plane (8-bit transmission per symbol) are prepared in thetransmission device. At this point, the following condition is satisfiedin the transmission device.

<Condition #28>

In the transmission device, one of <28-1>, <28-2>, <28-3>, and <28-4> issatisfied.

<28-1>

In s1(i), all the M kinds of signal point arrangement methods areadopted.

<28-2>

In s2(i), all the M kinds of signal point arrangement methods areadopted.

<28-3>

All the M kinds of signal point arrangement methods are adopted ins1(i), and all the M kinds of signal point arrangement methods are alsoadopted in s2(i).

<28-4>

In the case that signal point arrangement method adopted in s1(i) andthe signal point arrangement method adopted in s2(i) are combined, allthe M kinds of signal point arrangement methods are adopted.

The M kinds of mapping methods for the modulation scheme involving the256 signal points in the I-Q plane (8-bit transmission per symbol) areexpressed as “signal point arrangement $k of modulation scheme involving256 signal points” (k is an integer of 0 to M−1), whereby the followingcondition holds.

<Condition #29>

In the case that x is an integer of 0 to M−1, that y is an integer of 0to M−1, and that x≠y holds, the following matter holds in all integers xand y.

{

-   (I_(x,i),Q_(x,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $x of modulation    scheme involving 256 signal points”, and that (I_(y,j),Q_(y,j)) (j    is an integer of 0 to 255) represents coordinates of each of the 256    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $y of modulation scheme involving 256 signal points”. At    this point,-   {in the case that j is an integer of 0 to 255, i satisfying    I_(x,i)≠I_(y,j) exists in all integers j} or {in the case that j is    an integer of 0 to 255, i satisfying Q_(x,i)≠Q_(y,j) exists in all    integers j.}    }

Therefore, in the reception device, a possibility of regularlygenerating a small state of the minimum Euclid of each of 65536reception candidate signal points in the in-phase I-orthogonal Q planecan be lowered by satisfying these conditions (for example, in the casethat the direct wave is dominant in the radio wave propagationenvironment). Therefore, the reception device has a high possibility ofobtaining the high data reception quality.

The following matter holds in the case that “g=h” holds in signal pointarrangement $g of the modulation scheme involving the 256 signal pointsand signal point arrangement $h of the modulation scheme involving the256 signal points.

{

-   (I_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents    coordinates of each of the 256 signal points in the in-phase    I-orthogonal Q plane of “signal point arrangement $g of modulation    scheme involving 256 signal points”, and that (I_(h,j),Q_(h,j)) (j    is an integer of 0 to 255) represents coordinates of each of the 256    signal points in the in-phase I-orthogonal Q plane of “signal point    arrangement $h of modulation scheme involving 256 signal points”. At    this point,-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold exists in all integers k.}    }

Similarly, for “g h”, the following matter is satisfied.

{

(I_(g,i),Q_(g,i)) (i is an integer of 0 to 255) represents coordinatesof each of the 256 signal points in the in-phase I-orthogonal Q plane of“signal point arrangement $g of modulation scheme involving 256 signalpoints”, and that (I_(h,j),Q_(h,j)) (j is an integer of 0 to 255)represents coordinates of each of the 256 signal points in the in-phaseI-orthogonal Q plane of “signal point arrangement $h of modulationscheme involving 256 signal points”. At this point,

-   {in the case that that k is an integer of 0 to 255, the case that    I_(g,k)=I_(h,k) and Q_(g,k)=Q_(h,k) hold does not exist in integers    k.}    }

At this point, the mapping set is defined.

The mapping set is defined as “(signal point arrangement $p₁ ofmodulation scheme involving 256 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 256 s2(t) signalpoints)”.

At this point, the following matter holds in the same mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 256 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 256 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 256 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 256 s2(t) signal points),p₁=q₁ and p₂=q₂ hold in the case that the first mapping set is identicalto the second mapping set.”

The following matter holds in the different mapping set.

“When the first mapping set is (signal point arrangement $p₁ ofmodulation scheme involving 256 s1(t) signal points, signal pointarrangement $p₂ of modulation scheme involving 256 s2(t) signal points)while the second mapping set is (signal point arrangement $q₁ ofmodulation scheme involving 256 s1(t) signal points, signal pointarrangement $q₂ of modulation scheme involving 256 s2(t) signal points),p₁≠q₁ and p₂≠q₂ hold in the case that the first mapping set is differentfrom the second mapping set.”

At this point, the transmission device (the mapper in FIGS. 12 and 13)prepares L (L is an integer of 2 or more) kinds of mapping sets, andsets the L kinds of mapping sets to “mapping set *k” (k is an integer of0 to L−1). At this point, the L kinds of mapping sets satisfy thefollowing condition.

<Condition #30>

In the case that x is an integer of 0 to L−1, that y is an integer of 0to L−1, and that x≠y holds, “mapping set *x” differs from “mapping set*y” in all integers x and y.

The following condition is provided.

<Condition #31>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. At this point, all the N kinds of phase values of Phase[k] areused as phase change value θ.}

An example of <Condition #31> will be described below. Phase[0] andPhase[1] exist because N=2 kinds of phase values exist as the phasechange value. “Mapping set *0”, “mapping set *1”, and “mapping set *2”exist because L=3 kinds of mapping sets exist. At this point, FIG. 17illustrates the state in which <Condition #31>is satisfied.

In FIG. 17, the horizontal axis indicates time number (slot number) i.

First, attention is paid to “mapping set *0”. In time number 0, themapper in FIG. 12 or 13 performs the mapping using “mapping set *0”, andthe phase changer performs the phase change using Phase[0].

In time number 1, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *0”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *1”. In time number 2, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *1”, and the phasechanger performs the phase change using Phase[0].

In time number 3, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *0”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *1”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Attention is paid to “mapping set *2”. In time number 4, the mapper inFIG. 12 or 13 performs the mapping using “mapping set *2”, and the phasechanger performs the phase change using Phase[0].

In time number 5, the mapper in FIG. 12 or 13 performs the mapping using“mapping set *2”, and the phase changer performs the phase change usingPhase[1].

Accordingly, for “mapping set *2”, the phase changer in FIG. 12 or 13uses all the N=2 kinds of phase values of Phase[k].

Therefore, FIG. 17 satisfies <Condition #31>. Therefore, in thereception device, a possibility of regularly generating a small state ofthe minimum Euclid of each of 65536 reception candidate signal points inthe in-phase I-orthogonal Q plane can be lowered by satisfying theseconditions (for example, in the case that the direct wave is dominant inthe radio wave propagation environment). Therefore, the reception devicehas a high possibility of obtaining the high data reception quality.

The reception device has a possibility of obtaining the similaradvantage even if the following condition is satisfied instead of<Condition #31>.

<Condition #32>

In the case that x is an integer of 0 to L−1, the following matter issatisfied in all integers x.

{The phase changer (subsequent to the weighting composition part) inFIG. 12 or 13 (or FIG. 18, 19, 20, or 21) performs the phase change onthe signal generated using signals s1 and s2 generated using “mappingset *x”. All the N kinds of phase values of Phase[k] are used as phasechange value θ.}

In the exemplary embodiment, the OFDM scheme is applied by way ofexample. Alternatively, other multi-carrier schemes and single-carrierscheme can also be applied. An OFDM scheme (NPL 7) in which a wavelettransform is used and a spread spectrum communication scheme can also beapplied.

(Supplement)

The above exemplary embodiment may be performed while a plurality ofcontents are combined therewith.

The exemplary embodiment and other contents are illustrated only by wayof example. The exemplary embodiment and other contents can be achievedwith a similar configuration even with, for example, different“modulation scheme, error correction coding scheme (such as errorcorrection code, code length, and coding rate to be used), and controlinformation” from the illustrated “modulation scheme, error correctioncoding scheme (such as error correction code, code length, and codingrate to be used), control information”.

The exemplary embodiment and other contents can be achieved with amodulation scheme other than the modulation scheme illustrated herein.For example, APSK (Amplitude Phase Shift Keying) (such as 16 APSK, 64APSK, 128 APSK, 256 APSK, 1024 APSK, and 4096 APSK), PAM (PulseAmplitude Modulation) (such as 4 PAM, 8 PAM, 16 PAM, 64 PAM, 128 PAM,256 PAM, 1024 PAM, and 4096 PAM), PSK (Phase Shift Keying) (such asBPSK, QPSK, 8 PSK, 16 PSK, 64 PSK, 128 PSK, 256 PSK, 1024 PSK, and 4096PSK), and QAM (Quadrature Amplitude Modulation) (such as 4 QAM, 8 QAM,16 QAM, 64 QAM, 128 QAM, 256 QAM, 1024 QAM, and 4096 QAM) may beapplied, or uniform mapping and non-uniform mapping may be applied ineach modulation scheme.

The method for arranging 2, 4, 8, 16, 64, 128, 256, or 1024 signalpoints in the I-Q plane (a modulation scheme involving 2, 4, 8, 16, 64,128, 256, or 1024 signal points) is not limited to the methods forarranging signal points according to the modulation scheme of theexemplary embodiment. Accordingly, the function of outputting thein-phase component and the orthogonal component based on the pluralityof bits is the function of the mapper, and the function of subsequentlyperforming the pre-coding and the phase change is one effective functionof the present disclosure.

In the case that “∀” and “∃” exist in the specification, “∀” designatesa universal quantifier, and “∃” designates an existential quantifier.

In the case that a complex plane exists in the specification, forexample, a unit of phase such as an argument is called “radian”.

The use of the complex plane can display polar coordinates of thecomplex number in a polar form. If a complex number z=a+jb (a and b areintegers and j is an imaginary unit) corresponds to a point (a,b) on thecomplex plane and the point (a,b) is expressed as [r,θ] by the polarcoordinate, (Equation 53) holds, where a=r×cos θand b=r×sin θ hold (r isan absolute value of z (r=|z|) and phase change value θ is an argument).z=a+jb is expressed by r×e^(jθ)

[Mathematical formula 53]

r=√{square root over (a² +b ²)}  (Equation 53)

In the exemplary embodiment, the pre-coding weight and phase are changeon the time axis. However, as described above, the exemplary embodimentcan also be achieved even if the multi-carrier transmission scheme suchas the OFDM transmission is used. For example, when the pre-codingswitching method is changed according to the number of transmissionsignals, the reception device can recognize the method for switching thepre-coding weight and phase by obtaining information about the number oftransmission signals transmitted by the transmission device.

In the exemplary embodiment, the terminal reception device and theantenna may separately be configured. For example, the reception deviceincludes an interface which receives through a cable the signal that isreceived by the antenna or the signal that is received by the antennaand subjected to frequency conversion, and the reception device performsthe subsequent processing.

The data or information obtained by the reception device is convertedinto a picture and a sound, and the picture is displayed on a monitorwhile the sound is output from a speaker. The data or informationobtained by the reception device may be subjected to signal processingrelating to the picture and sound (or does not need to be subjected tosignal processing), and output from an RCA terminal (video terminal andaudio terminal), a USB (Universal Serial Bus), HDMI (registeredtrademark) (High-Definition Multimedia Interface), and digital terminal,which are included in the reception device.

In the exemplary embodiment, examples of equipment including thetransmission device include communication or broadcasting equipment suchas a broadcasting station, a base station, an access point, a terminal,and a mobile phone. In this case, examples of equipment including thereception device include communication equipment such as a televisionset, a radio set, a terminal, a personal computer, a mobile phone, anaccess point, and a base station. The transmission device and receptiondevice of the present disclosure may be equipment having a communicationfunction, and the equipment may be connectable through a certaininterface to a device, such as the television set, the radio set, thepersonal computer, and the mobile phone, which executes an application.

In the exemplary embodiment, the symbol except for the data symbol, forexample, a pilot symbol (such as a preamble, a unique word, a postamble,and a reference symbol) and a symbol for control information mayflexibly be arranged in the frame. Although the symbol is referred to asthe pilot symbol or the symbol for control information, the symbol mayflexibly be named, and the function itself is important.

For example, in the transmitter and the receiver, the pilot symbol onlyneeds to be a known symbol that is modulated using the PSK modulation(alternatively, the receiver may synchronize with the transmitter torecognize the symbol transmitted by the transmitter), and the receiverperforms frequency synchronization, time synchronization, channelestimation (estimation of CSI (Channel State Information)) (of eachmodulated signal), and signal detection using the pilot symbol.

The symbol for control information is used to transmit information thatneeds to be transmitted to a communication partner (such as themodulation scheme used in the communication, the error correction codingscheme, and the coding rate of the error correction coding scheme, andsetting information in a high-level layer) in order to conduct thecommunication except for the data (of the application).

The present disclosure is not limited to the exemplary embodiment, butvarious changes can be made. For example, the exemplary embodiment isdescribed on the assumption that the exemplary embodiment is implementedby a communication device. Alternatively, the communication method canbe implemented by software.

The pre-coding switching method is described above in the method fortransmitting the two modulated signals from the two antennas.Alternatively, the pre-coding weight (matrix) can also be changed as thepre-coding switching method in a method for performing the pre-coding onfour post-mapping signals to generate four modulated signals andtransmitting the four modulated signals from four antennas, namely, amethod for performing the pre-coding on N post-mapping signals togenerate N modulated signals and transmitting the N modulated signalsfrom N antennas.

Although the terms such as “pre-coding” and “pre-coding weight” are usedherein, the name does not matter, but the present disclosure disclosesthe signal processing.

The different pieces of data or the identical data may be transmitted bystreams s1(t) and s2(t).

For both the transmit antenna of the transmission device and the receiveantenna of the reception device, one antenna illustrated in the drawingsmay be constructed with a plurality of antennas.

It is necessary that the transmission device and the reception device benotified of the transmission method (an MIMO, an SISO, a spatio-temporalblock code, and an interleaving scheme), the modulation scheme, and theerror correction coding scheme as a parameter. However, thenotifications of the transmission method, the modulation scheme, and theerror correction coding scheme are occasionally omitted in the exemplaryembodiment. The parameter exists in the frame transmitted by thetransmission device, and the reception device changes the operation byobtaining the parameter.

The exemplary embodiment of the present disclosure includes thefollowing modes.

A transmission method according to a first disclosure includes: mappingprocessing of generating a plurality of first modulated signals s1 and aplurality of second modulated signals s2 using a first mapping scheme,the plurality of second modulated signals s2 being equal to theplurality of first modulated signals s1, and generating a plurality ofthird modulated signals s3 and a plurality of fourth modulated signalss4 using a second mapping scheme, the plurality of fourth modulatedsignals s4 being equal to the plurality of third modulated signals s3,each of the first mapping scheme and the second mapping scheme involving16 signal points, the first mapping scheme and the second mapping schemebeing different from each other in a signal point arrangement; phasechange processing of performing a phase change on the plurality ofsecond modulated signals s2 using all N kinds of phases, and performingthe phase change on the plurality of fourth modulated signals s4 usingall the N kinds of phases, the N being an integer of 2 or more; andtransmission processing of transmitting sequentially the plurality offirst modulated signals s1 and the plurality of third modulated signalss3 using a first antenna, transmitting each of the plurality of secondmodulated signals s2 subjected to the phase change using a secondantenna at a same frequency and a same time as a frequency and a time ofa corresponding one of the plurality of first modulated signals s1, andtransmitting each of the plurality of fourth modulated signals s4subjected to the phase change using the second antenna at a samefrequency and a same time as a frequency and a time of a correspondingmodulated signal of the plurality of third modulated signals s3.

A transmission device according to a second disclosure includes: mappingcircuitry which, in operation, generates a plurality of first modulatedsignals s1 and a plurality of second modulated signals s2 using a firstmapping scheme, the plurality of first modulated signals s1 being equalto the plurality of second modulated signals s2, and generates aplurality of third modulated signals s3 and a plurality of fourthmodulated signals s4 using a second mapping scheme, the plurality ofthird modulated signals s3 being equal to the plurality of fourthmodulated signals s4, each of the first mapping scheme and the secondmapping scheme involving 16 signal points, the first mapping scheme andthe second mapping scheme being different from each other in a signalpoint arrangement; phase change circuitry which, in operation, performsa phase change on the plurality of second modulated signals s2 using allN kinds of phases, and performs the phase change on the plurality offourth modulated signals s4 using all the N kinds of phases, the N beingan integer of 2 or more; and transmission circuitry which, in operation,transmits sequentially the plurality of first modulated signals s1 andthe plurality of third modulated signals s3 using a first antenna,transmits each of the plurality of second modulated signals s2 subjectedto the phase change using the second antenna at a same frequency and asame time as a frequency and a time of a corresponding modulated signalof the plurality of first modulated signals s1, and transmits each ofthe plurality of fourth modulated signals s4 subjected to the phasechange using the second antenna at a same frequency and a same time as afrequency and a time of a corresponding modulated signal of theplurality of third modulated signals s3.

A reception method according to a third disclosure includes: receptionprocessing of acquiring reception signals, the reception signals beingsignals obtained by sequentially receiving a plurality of firstmodulated signals s1, a plurality of third modulated signals s3, aplurality of second modulated signals s2, and a plurality of fourthmodulated signals s4, the plurality of first modulated signals s1 andthe plurality of third modulated signals s3 being sequentiallytransmitted from a first antenna, the plurality of second modulatedsignals s2 and the plurality of fourth modulated signals s4 beingsequentially transmitted from a second antenna, each of the plurality ofsecond modulated signals s2 being transmitted at a same frequency and asame time as a frequency and a time of a corresponding modulated signalof the plurality of first modulated signals s1, each of the plurality offourth modulated signals s4 being transmitted at a same frequency and asame time as a frequency and a time of a corresponding modulated signalof the plurality of third modulated signals s3, the plurality of secondmodulated signals s2 being modulated signals subjected to a phase changeusing all N kinds of phases before the transmission, the N being aninteger of 2 or more, the plurality of fourth modulated signals s4 beingmodulated signals subjected to the phase change using all the N kinds ofphases before the transmission, the plurality of first modulated signalss1 and the plurality of second modulated signals s2 being generatedusing a first mapping scheme, the plurality of first modulated signalss1 being equal to the plurality of second modulated signals s2, theplurality of pre-phase-change third modulated signals s3 and theplurality of pre-phase-change fourth modulated signals s4 beinggenerated using a second mapping scheme, the plurality ofpre-phase-change third modulated signals s3 being equal to the pluralityof pre-phase-change fourth modulated signals s4, each of the firstmapping scheme and the second mapping scheme involving 16 signal points,the first mapping scheme and the second mapping scheme being differentfrom each other in a signal point arrangement; and demodulationprocessing of demodulating the reception signals using a firstde-mapping scheme corresponding to the first mapping scheme and a secondde-mapping scheme corresponding to the second mapping scheme.

A reception device according to a fourth disclosure includes: receptioncircuitry which, in operation, acquires reception signals, the receptionsignals being signals obtained by sequentially receiving a plurality offirst modulated signals s1, a plurality of third modulated signals s3, aplurality of second modulated signals s2, and a plurality of fourthmodulated signals s4, the plurality of first modulated signals s1 andthe plurality of third modulated signals s3 being sequentiallytransmitted from a first antenna, the plurality of second modulatedsignals s2 and the plurality of fourth modulated signals s4 beingsequentially transmitted from a second antenna, each of the plurality ofsecond modulated signals s2 being transmitted at a same frequency and asame time as a frequency and a time of a corresponding modulated signalof the plurality of first modulated signals s1, each of the plurality offourth modulated signals s4 being transmitted at a same frequency and asame time as a frequency and a time of a corresponding modulated signalof the plurality of third modulated signals s3, the plurality of secondmodulated signals s2 being modulated signals subjected to a phase changeusing all N kinds of phases before the transmission, the N being aninteger of 2 or more, the plurality of fourth modulated signals s4 beingmodulated signals subjected to a phase change using all the N kinds ofphases before the transmission, the plurality of first modulated signalss1 and the plurality of second modulated signals s2 being generatedusing a first mapping scheme, the plurality of first modulated signalss1 being equal to the plurality of second modulated signals s2, theplurality of pre-phase-change third modulated signals s3 and theplurality of pre-phase-change fourth modulated signals s4 beinggenerated using a second mapping scheme, the plurality ofpre-phase-change third modulated signals s3 being equal to the pluralityof pre-phase-change fourth modulated signals s4, each of the firstmapping scheme and the second mapping scheme involving 16 signal points,the first mapping scheme and the second mapping scheme being differentfrom each other in a signal point arrangement; and demodulationcircuitry which, in operation, demodulates the reception signals using afirst de-mapping scheme corresponding to the first mapping scheme and asecond de-mapping scheme corresponding to the second mapping scheme.

For example, a program executing the communication method may previouslybe stored in a ROM (Read Only Memory), and executed by a CPU (CentralProcessor Unit).

The program for executing the communication method may be stored in acomputer-readable storage medium, the program stored in the storagemedium may be recorded in a RAM (Random Access Memory), and a computermay be operated according to the program.

Each configuration of the exemplary embodiment may typically beimplemented as an LSI (Large Scale Integration) that is of an integratedcircuit including an input terminal and an output terminal. Eachconfiguration of the exemplary embodiment may individually be integratedinto one chip, or all or some of the configurations of the exemplaryembodiment may be integrated into one chip.

Although the term LSI is used, sometimes the terms of an IC (IntegratedCircuit), a system LSI, a super LSI, and an ultra LSI are used. Acircuit integration technique is not limited to the LSI, but the circuitintegration technique may be implemented by a dedicated circuit or ageneral-purpose processor. A programmable FPGA (Field Programmable GateArray) or a reconfigurable processor that can reconfigure the connectionor setting of circuit cell in the LSI may be used after production ofthe LSI.

When a circuit integration technology that replacing the LSI emergeswith the progress of a semiconductor technology or a derivativetechnology, the functional blocks may be integrated using thetechnology. A biotechnology might be applied.

The present disclosure can widely be applied to a radio communicationsystem that transmits the different modulated signals from the pluralityof antennas. The present disclosure can be applied to the case that MIMOtransmission is performed in a wired communication system (such as a PLC(Power Line Communication) system, an optical communication system, anda DSL (Digital Subscriber Line) system) having a plurality oftransmission places.

1-4. (canceled)
 5. A transmission method comprising: generating a firstorthogonal frequency division modulated (OFDM) symbol and a second OFDMsymbol including first modulated signals s1(k) and second modulatedsignals s2(k), respectively, k denoting a carrier number, the secondmodulated signals s2(k) being equal to the first modulated signalss1(k), respectively, the first modulated signals s1(k) including 4-bitdata blocks each corresponding to any one of 16 signal points of a first16 Quadrature Amplitude Modulation (QAM) scheme; performing a firstphase change on the second modulated signals s2(k) to generate secondphase changed signals z2(k), the first phase change multiplying thesecond modulated signals s2(k)by respective coefficients e^(iθ(k)) wheree^(iθ(k)) is a function of k and θ(k) denotes an angle; transmitting thefirst OFDM symbol and the second OFDM symbol through a first antenna anda second antenna, respectively such that the first modulated signals1(k) and the second phase changed signal z2(k) are transmitted at asame frequency and a same time for each carrier number k; generating athird OFDM symbol and a fourth OFDM symbol including third modulatedsignals s3(k) and fourth modulated signals s4(k), respectively, thefourth modulated signals s4(k) being equal to the third modulatedsignals s3(k), respectively, the third modulated signals s3(k) including4-bit data blocks each corresponding to any one of 16 signal points of asecond 16 QAM scheme, a first arrangement pattern of the 16 signalpoints of the first 16 QAM scheme being different from a secondarrangement pattern of the 16 signal points of the second 16 QAM scheme;performing a second phase change on the fourth modulated signals s4(k)to generate fourth phase changed signals z4(k), the second phase changemultiplying the fourth modulated signals s4(k) by respectivecoefficients and transmitting the third OFDM symbol and the fourth OFDMsymbol through the first antenna and the second antenna, respectivelysuch that the third modulated signal s3(k) and the fourth phase changedsignal z4(k) are transmitted at a same frequency and a same time foreach carrier number k.
 6. The transmission method according to claim 5,wherein the first OFDM symbol and the second OFDM symbol each includepilot signals.
 7. A transmission system comprising: generating circuitryconfigured to generate a first orthogonal frequency division modulated(OFDM) symbol and a second OFDM symbol including first modulated signalss1(k) and second modulated signals s2(k), respectively, k denoting acarrier number, the second modulated signals s2(k) being equal to thefirst modulated signals s1(k), respectively, the first modulated signalss1(k) including 4-bit data blocks each corresponding to any one of 16signal points of a first 16 Quadrature Amplitude Modulation (QAM)scheme; phase change circuitry configured to perform a first phasechange on the second modulated signals s2(k) to generate second phasechanged signals z2(k), the first phase change multiplying each of thesecond modulated signals s2(k) by respective coefficients e^(iθ(k))where e^(iθ(k)) is a function of k and θ(k) denotes an angle; andtransmitting circuitry configured to transmit the first OFDM symbol andthe second OFDM symbol through a first antenna and a second antenna,respectively such that the first modulated signal s1(k) and the secondphase changed signal z2(k) are transmitted at a same frequency and asame time for each carrier number k, wherein the generating circuitry isconfigured to generate a third OFDM symbol and a fourth OFDM symbolincluding third modulated signals s3(k) and fourth modulated signalss4(k), respectively, the fourth modulated signals s4(k) being equal tothe third modulated signals s3(k), respectively, the third modulatedsignals s3(k) including 4-bit data blocks each corresponding to any oneof 16 signal points of a second 16 QAM scheme, a first arrangementpattern of the 16 signal points of the first 16 QAM scheme beingdifferent from a second arrangement pattern of the 16 signal points ofthe second 16 QAM scheme, the phase change circuitry is configured toperform a second phase change on the fourth modulated signals s4(k) togenerate fourth phase changed signals z4(k), the second phase changemultiplying each of the fourth modulated signals s4(k) by respectivecoefficients e^(iθ(k)), and the transmitting circuitry is configured totransmit the third OFDM symbol and the fourth OFDM symbol through thefirst antenna and the second antenna, respectively such that the thirdmodulated signal s3(k) and the fourth phase changed signal z4(k) aretransmitted at a same frequency and a same time for each carrier numberk.
 8. The transmission system according to claim 7, wherein the firstOFDM symbol and the second OFDM symbol each include pilot signals.
 9. Areception method comprising: receiving a first reception symbol obtainedby receiving a first orthogonal frequency division modulated (OFDM)symbol transmitted from a first antenna of a transmission system and asecond OFDM symbol transmitted from a second antenna of the transmissionsystem, the first OFDM symbol carrying first modulated signals s1(k),the second OFDM symbol carrying second phase changed signals z2(k), kdenoting a carrier number, the first modulated signal s1(k) and thesecond phase changed signal z2(k) are transmitted at a same frequencyand a same time for each carrier number k, the first modulated signalss1(k) including 4-bit data blocks each corresponding to any one of 16signal points of a first 16 Quadrature Amplitude Modulation (QAM)scheme, the second phase changed signals z2(k) being subjected to afirst phase change, the first phase change multiplying second modulatedsignals s2(k) by respective coefficients e^(iθ(k)) where e^(iθ(k)) is afunction of k and θ(k) denotes an angle, the second modulated signalss2(k)being equal to the first modulated signals s1(k), respectively; anddemodulating the first reception symbol using a first de-mapping schemecorresponding to the first 16 QAM scheme, receiving a second receptionsymbol obtained by receiving a third OFDM symbol transmitted from thefirst antenna and a fourth OFDM symbol transmitted from the secondantenna, the third OFDM symbol carrying third modulated signals s3(k),the fourth OFDM symbol carrying fourth phase changed signals z4(k), thethird modulated signal s3(k) and the fourth phase changed signal z4(k)are transmitted at a same frequency and a same time for each carriernumber k, the third modulated signals s3(k) including 4-bit data blockseach corresponding to any one of 16 signal points of a second 16 QAMscheme, a first arrangement pattern of the 16 signal points of the first16 QAM scheme being different from a second arrangement pattern of the16 signal points of the second 16 QAM scheme, the fourth phase changedsignals z4(k) being subjected to a second phase change, the second phasechange multiplying fourth modulated signals s4(k) by respectivecoefficients the fourth modulated signals s4(k) being equal to the thirdmodulated signals s3(k), respectively; and demodulating the secondreception symbol using a second de-mapping scheme corresponding to thesecond 16 QAM scheme.
 10. The reception method according to claim 9,wherein the first OFDM symbol and the second OFDM symbol each includepilot signals.